Work Power and Energy

142 questions · Physics · JEE Main

Work Power and Energy

142 questions · Physics · JEE Main

A particle is released from height $S$ above the surface of the earth. At certain height its kinetic energy is three times its potential energy. The height from the surface of the earth and the speed of the particle at that instant are…2025 · 3 Apr · Shift 1 · Q64 · MCQ
A block of mass 25 kg is pulled along a horizontal surface by a force at an angle $4 5^{\circ}$ with the horizontal. The friction coefficient between the block and the surface is 0.25 . The block travels at a uniform velocity. The work done…2025 · 4 Apr · Shift 2 · Q63 · MCQ
An object of mass 1000 g experiences a time dependent force $F = (2 t \hat{i} + 3 t^{2} \hat{j}) N$ . The power generated by the force at time $t$ is:2025 · 7 Apr · Shift 1 · Q53 · MCQ
Which one of the following forces cannot be expressed in terms of potential energy?2025 · 7 Apr · Shift 2 · Q55 · MCQ
A force $F = 2 \hat{i} + b \hat{j} + \hat{k}$ is applied on a particle and it undergoes a displacement $\hat{i} - 2 \hat{j} - \hat{k}$ What will be the value of $b$ , if work done on the particle is zero.2025 · 22 Jan · Shift 2 · Q69 · MCQ
A force $f = x^{2} y \hat{i} + y^{2} \hat{j}$ acts on a particle in a plane $x + y = 10$ . The work done by this force during a displacement from $(0, 0)$ to $(4 m, 2 m)$ …2025 · 23 Jan · Shift 1 · Q72 · Numerical
A ball having kinetic energy KE, is projected at an angle of $6 0^{\circ}$ from the horizontal. What will be the kinetic energy of ball at the highest point of its flight?2025 · 23 Jan · Shift 2 · Q58 · MCQ
A force $F = α + β x^{2}$ acts on an object in the x -direction. The work done by the force is 5 J when the object is displaced by 1 m . If the constant $α = 1 N$ then $β$ will be2025 · 24 Jan · Shift 1 · Q61 · MCQ
A bead of mass ' $m$ ' slides without friction on the wall of a vertical circular hoop of radius ' $R$ ' as shown in figure. The bead moves under the combined action of gravity and a massless spring (k) attached to the bottom of the hoop. The… Includes diagram2025 · 28 Jan · Shift 1 · Q51 · MCQ
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $R$ Assertion A: In a central force field, the work done is independent of the path chosen. Reason R: Every force encountered in…2025 · 28 Jan · Shift 1 · Q57 · MCQ
A body of mass 4 kg is placed on a plane at a point $P$ having coordinate $(3, 4) m$ . Under the action of force $F = (2 \hat{i} + 3 \hat{j}) N$ , it moves to a new point Q having coordinates $(6, 10) m$ …2025 · 28 Jan · Shift 2 · Q63 · MCQ
In a hydraulic lift, the surface area of the input piston is 6 cm2 and that of the output piston is 1500 cm2. If 100 N force is applied to the input piston to raise the output piston by 20 cm, then the work done is …2025 · 29 Jan · Shift 1 · Q71 · Numerical
A sand dropper drops sand of mass m(t) on a conveyer belt at a rate proportional to the square root of speed (v) of the belt, i.e., $\frac{d m}{d t} \propto v$ . If P is the power delivered to run the belt at constant speed then which…2025 · 29 Jan · Shift 2 · Q56 · MCQ
If a rubber ball falls from a height $h$ and rebounds upto the height of $h /2$ . The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are :2024 · 4 Apr · Shift 1 · Q66 · MCQ
A body of $m kg$ slides from rest along the curve of vertical circle from point $A$ to $B$ in friction less path. The velocity of the body at $B$ is: (given, $R = 14 m, g = 10 m / s^{2}$ and $2 = 1.4$ ) Includes diagram2024 · 4 Apr · Shift 2 · Q72 · MCQ
A body of mass $50 kg$ is lifted to a height of $20 m$ from the ground in the two different ways as shown in the figures. The ratio of work done against the gravity in both the respective cases, will be : Includes diagram2024 · 5 Apr · Shift 1 · Q61 · MCQ
A body is moving unidirectionally under the influence of a constant power source. Its displacement in time t is proportional to :2024 · 5 Apr · Shift 2 · Q61 · MCQ
A bullet of mass $50 g$ is fired with a speed $100 m / s$ on a plywood and emerges with $40 m / s$ . The percentage loss of kinetic energy is :2024 · 6 Apr · Shift 1 · Q61 · MCQ
Four particles $A, B, C, D$ of mass $\frac{m}{2}, m, 2 m, 4 m$ , have same momentum, respectively. The particle with maximum kinetic energy is :2024 · 6 Apr · Shift 1 · Q71 · MCQ
When kinetic energy of a body becomes 36 times of its original value, the percentage increase in the momentum of the body will be :2024 · 6 Apr · Shift 2 · Q75 · MCQ
Three bodies A, B and C have equal kinetic energies and their masses are $400 g, 1.2 kg$ and $1.6 kg$ respectively. The ratio of their linear momenta is :2024 · 8 Apr · Shift 1 · Q69 · MCQ
A block is simply released from the top of an inclined plane as shown in the figure above. The maximum compression in the spring when the block hits the spring is : Includes diagram2024 · 8 Apr · Shift 2 · Q62 · MCQ
A particle of mass $m$ moves on a straight line with its velocity increasing with distance according to the equation $v = α x$ , where $α$ is a constant. The total work done by all the forces applied on the particle during…2024 · 9 Apr · Shift 1 · Q67 · MCQ
A force $(3 x^{2} + 2 x - 5) N$ displaces a body from $x = 2 m$ to $x = 4 m$ . Work done by this force is J.2024 · 9 Apr · Shift 2 · Q85 · Numerical
A ball suspended by a thread swings in a vertical plane so that its magnitude of acceleration in the extreme position and lowest position are equal. The angle $(θ)$ of thread deflection in the extreme position will be :2024 · 27 Jan · Shift 2 · Q62 · MCQ
A bullet is fired into a fixed target looses one third of its velocity after travelling $4 cm$ . It penetrates further $D \times 1 0^{- 3} m$ before coming to rest. The value of $D$ is :2024 · 27 Jan · Shift 2 · Q71 · MCQ
A block of mass $100 kg$ slides over a distance of $10 m$ on a horizontal surface. If the co-efficient of friction between the surfaces is 0.4, then the work done against friction $(in J$ ) is :2024 · 29 Jan · Shift 1 · Q71 · MCQ
The potential energy function (in $J$ ) of a particle in a region of space is given as $U = (2 x^{2} + 3 y^{3} + 2 z)$ . Here $x, y$ and $z$ are in meter. The magnitude of $x$ -component of force (in $N$ ) acting on the particle at point $P (1, 2, 3) m$ …2024 · 29 Jan · Shift 1 · Q79 · MCQ
A bob of mass ' $m$ ' is suspended by a light string of length ' $L$ '. It is imparted a minimum horizontal velocity at the lowest point $A$ such that it just completes half circle reaching the top most position B. The ratio of kinetic… Includes diagram2024 · 29 Jan · Shift 2 · Q66 · MCQ
A particle is placed at the point $A$ of a frictionless track $A B C$ as shown in figure. It is gently pushed towards right. The speed of the particle when it reaches the point B is : (Take $g = 10 m / s^{2}$ ). Includes diagram2024 · 30 Jan · Shift 1 · Q68 · MCQ
A block of mass $1 kg$ is pushed up a surface inclined to horizontal at an angle of $6 0^{\circ}$ by a force of $10 N$ parallel to the inclined surface as shown in figure. When the block is pushed up by $10 m$ … Includes diagram2024 · 30 Jan · Shift 2 · Q80 · MCQ
A body of mass $2 kg$ begins to move under the action of a time dependent force given by $F = (6 t \hat{i} + 6 t^{2} \hat{j}) N$ . The power developed by the force at the time $t$ is given by:2024 · 31 Jan · Shift 2 · Q77 · MCQ
A small particle moves to position $5 \hat{i} - 2 \hat{j} + \hat{k}$ from its initial position $2 \hat{i} + 3 \hat{j} - 4 \hat{k}$ under the action of force $5 \hat{i} + 2 \hat{j} + 7 \hat{k} N$ . The value of work done will be …2023 · 1 Feb · Shift 1 · Q67 · Numerical
A block is fastened to a horizontal spring. The block is pulled to a distance $x = 10 cm$ from its equilibrium position (at $x = 0$ ) on a frictionless surface from rest. The energy of the block at $x = 5 cm$ is $0.25 J$ …2023 · 1 Feb · Shift 2 · Q66 · Numerical
A force $F = (5 + 3 y^{2})$ acts on a particle in the $y$ -direction, where $F$ is in newton and $y$ is in meter. The work done by the force during a displacement from $y = 2 m$ to $y = 5 m$ is …2023 · 1 Feb · Shift 2 · Q71 · Numerical
A particle of mass $10 g$ moves in a straight line with retardation $2 x$ , where $x$ is the displacement in SI units. Its loss of kinetic energy for above displacement is $(\frac{10}{x})^{- n}$ J. The value of $n$ …2023 · 6 Apr · Shift 1 · Q67 · Numerical
A body is dropped on ground from a height ' $h_{1}$ ' and after hitting the ground, it rebounds to a height ' $h_{2}$ '. If the ratio of velocities of the body just before and after hitting ground is 4 , then percentage loss in kinetic energy…2023 · 6 Apr · Shift 2 · Q67 · Numerical
A bullet of mass $0.1 kg$ moving horizontally with speed $400 ms^{- 1}$ hits a wooden block of mass $3.9 kg$ kept on a horizontal rough surface. The bullet gets embedded into the block and moves $20…2023 · 8 Apr · Shift 2 · Q46 · MCQ
A body of mass $5 kg$ is moving with a momentum of $10 kg ms^{- 1}$ . Now a force of $2 N$ acts on the body in the direction of its motion for $5 s$ . The increase in the Kinetic energy of the…2023 · 8 Apr · Shift 2 · Q61 · Numerical
A closed circular tube of average radius 15 cm, whose inner walls are rough, is kept in vertical plane. A block of mass 1 kg just fit inside the tube. The speed of block is 22 m/s, when it is introduced at the top of tube. After completing… Includes diagram2023 · 10 Apr · Shift 1 · Q69 · Numerical
If the maximum load carried by an elevator is $1400 kg$ ( $600 kg$ - Passengers + 800 $kg$ - elevator), which is moving up with a uniform speed of $3 m s^{- 1}$ and the frictional force acting on…2023 · 10 Apr · Shift 2 · Q61 · Numerical
A force $F = (2 + 3 x) \hat{i}$ acts on a particle in the $x$ direction where F is in newton and $x$ is in meter. The work done by this force during a displacement from $x = 0$ to $x = 4 m$ , is J.2023 · 11 Apr · Shift 1 · Q71 · Numerical
A block of mass $5 kg$ starting from rest pulled up on a smooth incline plane making an angle of $3 0^{\circ}$ with horizontal with an affective acceleration of $1 ms^{- 2}$ . The power delivered by the pulling force at $t = 10 s$ …2023 · 11 Apr · Shift 2 · Q67 · Numerical
Given below are two statements: Statement I : A truck and a car moving with same kinetic energy are brought to rest by applying breaks which provide equal retarding forces. Both come to rest in equal distance. Statement II : A car moving…2023 · 12 Apr · Shift 1 · Q45 · MCQ
To maintain a speed of 80 km/h by a bus of mass 500 kg on a plane rough road for 4 km distance, the work done by the engine of the bus will be KJ. [The coefficient of friction between tyre of bus and road is…2023 · 12 Apr · Shift 1 · Q60 · Numerical
The ratio of powers of two motors is $\frac{3 x}{x + 1}$ , that are capable of raising $300 kg$ water in 5 minutes and $50 kg$ water in 2 minutes respectively from a well of $100 m$ deep. The value…2023 · 13 Apr · Shift 1 · Q62 · MCQ
Two bodies are having kinetic energies in the ratio 16 : 9. If they have same linear momentum, the ratio of their masses respectively is :2023 · 13 Apr · Shift 1 · Q63 · MCQ
A car accelerates from rest to $u m / s$ . The energy spent in this process is E J. The energy required to accelerate the car from $u m / s$ to $2 um / s$ is $nE J$ .…2023 · 13 Apr · Shift 2 · Q71 · Numerical
A block of mass $10 kg$ is moving along $x$ -axis under the action of force $F = 5 x N$ . The work done by the force in moving the block from $x = 2 m$ to $4 m$ will be J.2023 · 15 Apr · Shift 1 · Q68 · Numerical
A spherical body of mass 2 kg starting from rest acquires a kinetic energy of 10000 J at the end of $5^{th}$ second. The force acted on the body is N.2023 · 24 Jan · Shift 1 · Q70 · Numerical
A body of mass 1kg begins to move under the action of a time dependent force $F = (t i + 3 t^{2} j)$ N, where $i$ and $j$ are the unit vectors along $x$ and $y$ axis. The…2023 · 24 Jan · Shift 2 · Q65 · Numerical
An object of mass 'm' initially at rest on a smooth horizontal plane starts moving under the action of force F = 2N. In the process of its linear motion, the angle $θ$ (as shown in figure) between the direction of force and horizontal… Includes diagram2023 · 25 Jan · Shift 1 · Q65 · Numerical
A stone is projected at angle $3 0^{\circ}$ to the horizontal. The ratio of kinetic energy of the stone at point of projection to its kinetic energy at the highest point of flight will be -2023 · 29 Jan · Shift 1 · Q55 · MCQ
A 0.4 kg mass takes 8s to reach ground when dropped from a certain height 'P' above surface of earth. The loss of potential energy in the last second of fall is J. (Take g = 10 m/s $^{2}$ )2023 · 29 Jan · Shift 1 · Q71 · Numerical
Identify the correct statements from the following : A. Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket is negative. B. Work done by gravitational force in lifting a bucket out of a well by a rope…2023 · 29 Jan · Shift 2 · Q50 · MCQ
A body of mass $2 kg$ is initially at rest. It starts moving unidirectionally under the influence of a source of constant power P. Its displacement in $4 s$ is $\frac{1}{3} α^{2} P m$ . The value of $α$ …2023 · 30 Jan · Shift 2 · Q68 · Numerical
A lift of mass $M = 500 kg$ is descending with speed of $2 ms^{- 1}$ . Its supporting cable begins to slip thus allowing it to fall with a constant acceleration of $2 ms^{- 2}$ . The kinetic energy of the…2023 · 31 Jan · Shift 1 · Q65 · Numerical
A particle experiences a variable force $F = (4 x i + 3 y^{2} j)$ in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2,…2022 · 24 Jun · Shift 1 · Q52 · MCQ
A ball of mass 100 g is dropped from a height h = 10 cm on a platform fixed at the top of a vertical spring (as shown in figure). The ball stays on the platform and the platform is depressed by a distance $\frac{h}{2}$ . The spring constant… Includes diagram2022 · 24 Jun · Shift 1 · Q68 · Numerical
A body of mass $0.5 kg$ travels on straight line path with velocity $v = (3 x^{2} + 4) m / s$ . The net workdone by the force during its displacement from $x = 0$ to $x = 2 m$ is :2022 · 25 Jul · Shift 1 · Q44 · MCQ
A bag of sand of mass 9.8 kg is suspended by a rope. A bullet of 200 g travelling with speed 10 ms $-$ 1 gets embedded in it, then loss of kinetic energy will be :2022 · 25 Jul · Shift 2 · Q59 · MCQ
A uniform chain of 6 m length is placed on a table such that a part of its length is hanging over the edge of the table. The system is at rest. The co-efficient of static friction between the chain and the surface of the table is 0.5, the…2022 · 25 Jun · Shift 1 · Q62 · Numerical
A 0.5 kg block moving at a speed of 12 ms $-$ 1 compresses a spring through a distance 30 cm when its speed is halved. The spring constant of the spring will be Nm $-$ 1.2022 · 25 Jun · Shift 1 · Q63 · Numerical
As per the given figure, two blocks each of mass $250 g$ are connected to a spring of spring constant $2 Nm^{- 1}$ . If both are given velocity $v$ in opposite directions, then maximum elongation of the spring is : Includes diagram2022 · 26 Jul · Shift 1 · Q60 · MCQ
Arrange the four graphs in descending order of total work done; where W1, W2, W3 and W4 are the work done corresponding to figure a, b, c and d respectively. Includes diagram2022 · 26 Jun · Shift 2 · Q49 · MCQ
Sand is being dropped from a stationary dropper at a rate of $0.5 kgs^{- 1}$ on a conveyor belt moving with a velocity of $5 ms^{- 1}$ . The power needed to keep the belt moving with the same velocity will be :2022 · 27 Jul · Shift 1 · Q49 · MCQ
A block of mass ' $m$ ' (as shown in figure) moving with kinetic energy E compresses a spring through a distance $25 cm$ when, its speed is halved. The value of spring constant of used spring will be $nE Nm^{- 1}$ … Includes diagram2022 · 28 Jul · Shift 1 · Q69 · Numerical
A bullet of mass $200 g$ having initial kinetic energy $90 J$ is shot inside a long swimming pool as shown in the figure. If it's kinetic energy reduces to $40 J$ within $1 s$ , the minimum length of… Includes diagram2022 · 28 Jul · Shift 2 · Q44 · MCQ
A ball is projected with kinetic energy E, at an angle of $6 0^{\circ}$ to the horizontal. The kinetic energy of this ball at the highest point of its flight will become :2022 · 29 Jul · Shift 1 · Q52 · MCQ
A particle of mass 500 gm is moving in a straight line with velocity v = b x5/2. The work done by the net force during its displacement from x = 0 to x = 4 m is : (Take b = 0.25 m $-$ 3/2 s $-$ 1).2022 · 29 Jun · Shift 1 · Q48 · MCQ
In the given figure, the block of mass m is dropped from the point 'A'. The expression for kinetic energy of block when it reaches point 'B' is Includes diagram2022 · 29 Jun · Shift 2 · Q57 · MCQ
A body of mass 'm' dropped from a height 'h' reaches the ground with a speed of 0.8 $g h$ . The value of workdone by the air-friction is :2021 · 1 Sep · Shift 2 · Q50 · MCQ
An engine is attached to a wagon through a shock absorber of length 1.5 m. The system with a total mass of 40,000 kg is moving with a speed of 72 kmh $-$ 1 when the brakes are applied to bring it to rest. In the process of the system being…2021 · 1 Sep · Shift 2 · Q74 · Numerical
A boy is rolling a 0.5 kg ball on the frictionless floor with the speed of 20 ms-1. The ball gets deflected by an obstacle on the way. After deflection it moves with 5% of its initial kinetic energy. What is the speed of the ball now?2021 · 17 Mar · Shift 1 · Q43 · MCQ
As shown in the figure, a particle of mass 10 kg is placed at a point A. When the particle is slightly displaced to its right, it starts moving and reaches the point B. The speed of the particle at B is x m/s. (Take g = 10 m/s2) The value… Includes diagram2021 · 18 Mar · Shift 1 · Q69 · Numerical
A constant power delivering machine has towed a box, which was initially at rest, along a horizontal straight line. The distance moved by the box in time 't' is proportional to :-2021 · 18 Mar · Shift 1 · Q72 · MCQ
A ball of mass 4 kg, moving with a velocity of 10 ms $-$ 1, collides with a spring of length 8 m and force constant 100 Nm $-$ 1. The length of the compressed spring is x m. The value of x, to the nearest integer, is …2021 · 18 Mar · Shift 2 · Q64 · Numerical
In a spring gun having spring constant 100 N/m a small ball 'B' of mass 100 g is put in its barrel (as shown in figure) by compressing the spring through 0.05 m. There should be a box placed at a distance 'd' on the ground so that the ball… Includes diagram2021 · 20 Jul · Shift 1 · Q65 · Numerical
A body at rest is moved along a horizontal straight line by a machine delivering a constant power. The distance moved by the body in time 't' is proportional to :2021 · 20 Jul · Shift 2 · Q60 · MCQ
A porter lifts a heavy suitcase of mass 80 kg and at the destination lowers it down by a distance of 80 cm with a constant velocity. Calculate the work done by the porter in lowering the suitcase. (take g = 9.8 ms $-$ 2)2021 · 22 Jul · Shift 2 · Q50 · MCQ
The potential energy (U) of a diatomic molecule is a function dependent on r (interatomic distance) as $U = \frac{α}{r ^{10}} - \frac{β}{r ^{5}} - 3$ where, $α$ and $β$ are positive constants. The equilibrium…2021 · 25 Feb · Shift 1 · Q68 · Numerical
A force of F = (5y + 20) $j$ N acts on a particle. The work done by this force when the particle is moved from y = 0 m to y = 10 m is J.2021 · 25 Jul · Shift 2 · Q69 · Numerical
A uniform chain of length 3 meter and mass 3 kg overhangs a smooth table with 2 meter lying on the table. If k is the kinetic energy of the chain in joule as it completely slips off the table, then the value of k is ................. .…2021 · 26 Aug · Shift 1 · Q63 · Numerical
Two persons A and B perform same amount of work in moving a body through a certain distance d with application of forces acting at angle 45 $^{\circ}$ and 60 $^{\circ}$ with the direction of displacement respectively. The ratio of force…2021 · 27 Aug · Shift 1 · Q65 · Numerical
Given below is the plot of a potential energy function U(x) for a system, in which a particle is in one dimensional motion, while a conservative force F(x) acts on it. Suppose that Emech = 8 J, the incorrect statement for this system is :… Includes diagram2021 · 27 Jul · Shift 2 · Q51 · MCQ
An automobile of mass 'm' accelerates starting from origin and initially at rest, while the engine supplies constant power P. The position is given as a function of time by :2021 · 27 Jul · Shift 2 · Q59 · MCQ
A small block slides down from the top of hemisphere of radius R = 3 m as shown in the figure. The height 'h' at which the block will lose contact with the surface of the sphere is m. (Assume there is no friction… Includes diagram2021 · 27 Jul · Shift 2 · Q69 · Numerical
A block moving horizontally on a smooth surface with a speed of 40 ms $-$ 1 splits into two equal parts. If one of the parts moves at 60 ms $-$ 1 in the same direction, then the fractional change in the kinetic energy will be x : 4 where x…2021 · 31 Aug · Shift 1 · Q69 · Numerical
A block moving horizontally on a smooth surface with a speed of 40 m/s splits into two parts with masses in the ratio of 1 : 2. If the smaller part moves at 60 m/s in the same direction, then the fractional change in kinetic energy is :-2021 · 31 Aug · Shift 2 · Q58 · MCQ
A small block starts slipping down from a point B on an inclined plane AB, which is making an angle $θ$ with the horizontal section BC is smooth and the remaining section CA is rough with a coefficient of friction $μ$ . It is found… Includes diagram2020 · 2 Sep · Shift 1 · Q47 · Numerical
A cricket ball of mass 0.15 kg is thrown vertically up by a bowling machine so that it rises to a maximum height of 20 m after leaving the machine. If the part pushing the ball applies a constant force F on the ball and moves horizontally…2020 · 3 Sep · Shift 1 · Q46 · Numerical
A block starts moving up an inclined plane of inclination 30o with an initial velocity of v0 . It comes back to its initial position with velocity $\frac{v _{0}}{2}$ . The value of the coefficient of kinetic friction between the block and…2020 · 3 Sep · Shift 2 · Q43 · Numerical
A particle is moving unidirectionally on a horizontal plane under the action of a constant power supplying energy source. The displacement (s) - time (t) graph that describes the motion of the particle is (graphs are drawn schematically…2020 · 3 Sep · Shift 2 · Q60 · MCQ
A person pushes a box on a rough horizontal plateform surface. He applies a force of 200 N over a distance of 15 m. Thereafter, he gets progressively tired and his applied force reduces linearly with distance to 100 N. The total distance…2020 · 4 Sep · Shift 2 · Q52 · MCQ
A body of mass 2 kg is driven by an engine delivering a constant power of 1 J/s. The body starts from rest and moves in a straight line. After 9 seconds, the body has moved a distance (in m) .2020 · 5 Sep · Shift 2 · Q54 · Numerical
If the potential energy between two molecules is given by U = $- \frac{A}{r ^{6}} + \frac{B}{r ^{12}}$ , then at equilibrium, separation between molecules, and the potential energy are :2020 · 6 Sep · Shift 1 · Q52 · MCQ
A particle (m = 1 kg) slides down a frictionless track (AOC) starting from rest at a point A (height 2 m). After reaching C, the particle continues to move freely in air as a projectile. When it reaching its highest point P (height 1 m),… Includes diagram2020 · 7 Jan · Shift 1 · Q46 · Numerical
A 60 HP electric motor lifts an elevator having a maximum total load capacity of 2000 kg. If the frictional force on the elevator is 4000 N, the speed of the elevator at full load is close to : (1 HP = 746 W, g = 10 ms-2)2020 · 7 Jan · Shift 1 · Q62 · MCQ
An elevator in a building can carry a maximum of 10 persons, with the average mass of each person being 68 kg, The mass of the elevator itself is 920 kg and it moves with a constant speed of 3 m/s. The frictional force opposing the motion…2020 · 7 Jan · Shift 2 · Q48 · MCQ
Consider a force $F = - x i + y j$ . The work done by this force in moving a particle from point A(1, 0) to B(0, 1) along the line segment is : (all quantities are in SI units) Includes diagram2020 · 9 Jan · Shift 1 · Q59 · MCQ
A particle moves in one dimension from rest under the influence of a force that varies with the distance travelled by the particle as shown in the figure. The kinetic energy of the particle after it has travelled 3m is : Includes diagram2019 · 8 Apr · Shift 1 · Q53 · MCQ
A uniform cable of mass 'M' and length 'L' is placed on a horizontal surface such that its (1/n)th part is hanging below the edge of the surface. To lift the hanging part of the cable upto the surface, the work done should be :2019 · 9 Apr · Shift 1 · Q51 · MCQ
A block of mass m, lying on a smooth horizontal surface, is attached to a sring (of negligible mass) of spring constant k. The other end of the spring is fixed, as shown in the figure. The block is initially at rest in its equilibrium… Includes diagram2019 · 9 Jan · Shift 1 · Q58 · MCQ
A force acts on a 2 kg object so that its position is given as a function of time as x = 3t2 + 5. What is the work done by this force in first 5 seconds ?2019 · 9 Jan · Shift 2 · Q70 · MCQ
A block of mass m is kept on a platform which starts from rest with constant acceleration g/2 upward, as shown in figure. Work done by normal reaction on block in time is - Includes diagram2019 · 10 Jan · Shift 1 · Q69 · MCQ
A particle which is experiencing a force, given by $F = 3 i - 12 j,$ undergoes a displacement of $d = 4 i$ particle had a kinetic energy of 3 J at the beginning of the…2019 · 10 Jan · Shift 2 · Q61 · MCQ
Two particles of the same mass m are moving in circular orbits because of force, given by $F (r) = \frac{- 16}{r} - r^{3}$ The first particle is at a distance r = 1, and the second, at r = 4. The best estimate for the…2018 · 16 Apr · Shift 1 · Q66 · MCQ
A body of mass m starts moving from rest along x-axis so that its velocity varies as $υ = a s$ where a is a constant and s is the distance covered by the body. The total work done by all the forces acting on the body in the…2018 · 16 Apr · Shift 1 · Q67 · MCQ
A particle is moving in a circular path of radius $a$ under the action of an attractive potential $U = - \frac{k}{2 r ^{2}}$ Its total energy is:2018 · Shift 0 · Q61 · MCQ
An object is dropped from a height h from the ground. Every time it hits the ground it looses 50% of its kinetic energy. The total distance covered as t $\to \infty$ is :2017 · 8 Apr · Shift 1 · Q65 · MCQ
A time dependent force F = 6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the force during the first 1 sec. will be:2017 · Shift 0 · Q64 · MCQ
A body of mass m = 10–2 kg is moving in a medium and experiences a frictional force F = –kv2. Its initial speed is v0 = 10 ms–1. If, after 10 s, its energy is $\frac{1}{8} m v_{0}^{2}$ , the value of k will be:2017 · Shift 0 · Q65 · MCQ
A car of weight W is on an inclined road that rises by 100 m over a distance of 1 km and applies a constant frictional force $\frac{W}{20}$ on the car. While moving uphill on the road at a speed of 10 ms−1, the car needs power P. If it…2016 · 9 Apr · Shift 1 · Q64 · MCQ
Velocity-time graph for a body of mass 10 kg is shown in figure. Work-done on the body in first two seconds of the motion is : Includes diagram2016 · 10 Apr · Shift 1 · Q46 · MCQ
A particle of mass M is moving in a circle of fixed radius R in such a way that its centripetal acceleration at time t is given by n2 R t2 where n is a constant. The power delivered to the particle by the force acting on it, is :2016 · 10 Apr · Shift 1 · Q61 · MCQ
A point particle of mass $m,$ moves long the uniformly rough track $P QR$ as shown in the figure. The coefficient of friction, between the particle and the rough track equals $μ .$ The particle is released, from rest from the point $P$ … Includes diagram2016 · Shift 0 · Q59 · MCQ
A person trying to lose weight by burning fat lifts a mass of $10 k g$ upto a height of $1 m 1000$ times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done…2016 · Shift 0 · Q61 · MCQ
When a rubber-band is stretched by a distance $x$ , it exerts restoring force of magnitude $F = a x + b x^{2}$ where $a$ and $b$ are constants. The work done in stretching the unstretched rubber-band by $L$ is :2014 · Shift 0 · Q71 · MCQ
This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements, choose the one that best describes the two Statements. If two springs $S_{1}$ and $S_{2}$ of force constants $k_{1}$ and $k_{2}$ ,…2012 · Shift 0 · Q65 · MCQ
The potential energy function for the force between two atoms in a diatomic molecule is approximately given by $U (x) = \frac{a}{x ^{12}} - \frac{b}{x ^{6}},$ where $a$ and $b$ are constants and $x$ is the distance…2010 · Shift 0 · Q75 · MCQ
An athlete in the olympic games covers a distance of $100 m$ in $10 s .$ His kinetic energy can be estimated to be in the range2008 · Shift 0 · Q84 · MCQ
A $2 k g$ block slides on a horizontal floor with a speed of $4 m / s .$ It strikes a uncompressed spring, and compress it till the block is motionless. The kinetic friction force is $15 N$ and spring constant is $10, 000 N / m .$ The spring…2007 · Shift 0 · Q83 · MCQ
A particle is projected at $6 0^{\circ}$ to the horizontal with a kinetic energy K. The kinetic energy at the highest point is2007 · Shift 0 · Q99 · MCQ
A mass of $M k g$ is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of $4 5^{\circ}$ with the initial vertical direction is2006 · Shift 0 · Q123 · MCQ
A ball of mass $0.2 k g$ is thrown vertically upwards by applying a force by hand. If the hand moves $0.2 m$ while applying the force and the ball goes upto $2 m$ height further, find the magnitude of the force. (consider $g = 10 m / s^{2}$ ).2006 · Shift 0 · Q124 · MCQ
A particle of mass $100 g$ is thrown vertically upwards with a speed of $5 m / s$ . The work done by the force of gravity during the time the particle goes up is2006 · Shift 0 · Q127 · MCQ
The potential energy of a $1 k g$ particle free to move along the $x$ -axis is given by $V (x) = (\frac{x ^{4}}{4} - \frac{x ^{2}}{2}) J$ . The total mechanical energy of the particle is $2 J .$ Then, the maximum…2006 · Shift 0 · Q128 · MCQ
A bullet fired into a fixed target loses half of its velocity after penetrating $3 c m .$ How much further it will penetrate before coming to rest assuming that it faces constant resistance to motion?2005 · Shift 0 · Q173 · MCQ
The upper half of an inclined plane with inclination $ϕ$ is perfectly smooth while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is…2005 · Shift 0 · Q178 · MCQ
A body of mass $m$ is accelerated uniformly from rest to a speed $v$ in a time $T .$ The instantaneous power delivered to the body as a function of time is given by2005 · Shift 0 · Q179 · MCQ
A spherical ball of mass $20 k g$ is stationary at the top of a hill of height $100 m$ . It rolls down a smooth surface to the ground, then climbs up another hill of height $30 m$ and finally rolls down to a horizontal base at a height of $20 m$ …2005 · Shift 0 · Q180 · MCQ
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $x$ is proportional to2004 · Shift 0 · Q157 · MCQ
A uniform chain of length $2 m$ is kept on a table such that a length of $60 c m$ hangs freely from the edge of the table. The total mass of the chain is $4 k g .$ What is the work done in pulling the entire chain on the table?2004 · Shift 0 · Q158 · MCQ
A force $F = (5 i + 3 j + 2 k) N$ is applied over a particle which displaces it from its origin to the point $r = (2 i - j) m .$ …2004 · Shift 0 · Q159 · MCQ
A body of mass $^{'} m^{'},$ acceleration uniformly from rest to $^{'} v_{1}^{'}$ in time $T$ . The instantaneous power delivered to the body as a function of time is given by2004 · Shift 0 · Q160 · MCQ
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particles takes place in a plane. It follows that2004 · Shift 0 · Q161 · MCQ
A body is moved along a straight line by a machine delivering a constant power. The distance moved by the body in time $^{'} t^{'}$ is proportional to2003 · Shift 0 · Q157 · MCQ
A wire suspended vertically from one of its ends is stretched by attaching a weight of $200 N$ to the lower end. The weight stretches the wire by $1 mm .$ Then the elastic energy stored in the wire is2003 · Shift 0 · Q181 · MCQ
A spring of spring constant $5 \times 1 0^{3} N / m$ is stretched initially by $5 c m$ from the unstretched position. Then the work required to stretch it further by another $5 c m$ is2003 · Shift 0 · Q182 · MCQ
A spring of force constant $800 N / m$ has an extension of $5 c m .$ The work done in extending it from $5 c m$ to $15 c m$ is2002 · Shift 0 · Q143 · MCQ
A ball whose kinetic energy E, is projected at an angle of $4 5^{\circ}$ to the horizontal. The kinetic energy of the ball at the highest point of its height will be2002 · Shift 0 · Q168 · MCQ
If a body looses half of its velocity on penetrating $3 c m$ in a wooden block, then how much will it penetrate more before coming to rest?2002 · Shift 0 · Q170 · MCQ