Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Motion in A Straight Line question

2021 · 18 Mar · Shift 2 · Q52
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Physics
  4. /Motion in A Straight Line
  5. /2021 · 18 Mar · Shift 2 · Q52

Motion in A Straight Line question

2021 · 18 Mar · Shift 2 · Q52

JEE MainPhysicsMotion in A Straight LineMCQ+4 / −1
The velocity −-− displacement graph of a particle is shown in the figure. JEE Main 2021 (Online) 18th March Evening Shift Physics - Motion in a Straight Line Question 70 English The acceleration −-− displacement graph of the same particle is represented by :
  1. A
    JEE Main 2021 (Online) 18th March Evening Shift Physics - Motion in a Straight Line Question 70 English Option 1
  2. B
    JEE Main 2021 (Online) 18th March Evening Shift Physics - Motion in a Straight Line Question 70 English Option 2
  3. C
    JEE Main 2021 (Online) 18th March Evening Shift Physics - Motion in a Straight Line Question 70 English Option 3
  4. D
    JEE Main 2021 (Online) 18th March Evening Shift Physics - Motion in a Straight Line Question 70 English Option 4
View written solutionFree

Correct answer: A

The question refers to a velocity–displacement graph, and asks for the corresponding acceleration–displacement graph.

However, the actual figure and the option graphs are not visible in the provided prompt. So the exact graph cannot be identified from the given information alone.

Still, the relation needed to convert a vvv–xxx graph into an aaa–xxx graph is:

1. Key relation

We use a=dvdta = \frac{dv}{dt}a=dtdv​ and since dvdt=dvdx⋅dxdt=vdvdx,\frac{dv}{dt} = \frac{dv}{dx}\cdot \frac{dx}{dt} = v\frac{dv}{dx},dtdv​=dxdv​⋅dtdx​=vdxdv​, we get a(x)=v(x) dvdx.\boxed{a(x)=v(x)\,\frac{dv}{dx}}.a(x)=v(x)dxdv​​.

So, from a given velocity–displacement graph:

  1. Read vvv at each displacement xxx.
  2. Find the slope dvdx\dfrac{dv}{dx}dxdv​ at that point.
  3. Multiply them: a=vdvdx.a=v\frac{dv}{dx}.a=vdxdv​.

2. How the graph would be obtained

  • If the vvv–xxx graph is a straight line with positive slope, then v=mx+cv = mx + cv=mx+c so a=vdvdx=(mx+c)m=m2x+mc,a = v\frac{dv}{dx} = (mx+c)m = m^2x+mc,a=vdxdv​=(mx+c)m=m2x+mc, which is a straight line in aaa–xxx.

  • If the vvv–xxx graph is horizontal, then dvdx=0  ⟹  a=0.\frac{dv}{dx}=0 \implies a=0.dxdv​=0⟹a=0.

  • If the vvv–xxx graph decreases linearly, then dvdx<0\dfrac{dv}{dx}<0dxdv​<0, so the sign of acceleration depends on the sign of vvv.

3. Limitation here

Because the actual figure and option graphs are missing, I cannot independently derive which of A, B, C, or D matches.

The stored correct answer is A, but without the graph, this cannot be verified from first principles.

So the best I can do is state the governing relation: a=vdvdx\boxed{a=v\frac{dv}{dx}}a=vdxdv​​ and note that the exact option depends on the unseen figure.

PreviousNext

More from Motion in A Straight Line

  • A boy reaches the airport and finds that the escalator is not working. He walks up the stationary escalator in time t1. If he remains stationary on a moving escalator then the escalator takes him up in time t2. The time taken by him to…2021 · MCQ
  • If the velocity-time graph has the shape AMB, what would be the shape of the corresponding acceleration-time graph? Includes diagram2021 · MCQ
  • An engine of a train, moving with uniform acceleration, passes the signal-post with velocity u and the last compartment with velocity v. The velocity with which middle point of the train passes the signal post is :2021 · MCQ
  • A stone is dropped from the top of a building. When it crosses a point 5 m below the top, another stone starts to fall from a point 25 m below the top. Both stones reach the bottom of building simultaneously. The height of the building is :2021 · MCQ
  • Water droplets are coming from an open tap at a particular rate. The spacing between a droplet observed at 4th second after its fall to the next droplet is 34.3 m. At what rate the droplets are coming from the tap ? (Take g = 9.8 m/s2)2021 · MCQ
  • The relation between time t and distance x for a moving body is given as t = mx2 + nx, where m and n are constants. The retardation of the motion is : (When v stands for velocity)2021 · MCQ
  • A balloon was moving upwards with a uniform velocity of 10 m/s. An object of finite mass is dropped from the balloon when it was at a height of 75 m from the ground level. The height of the balloon from the ground when object strikes the…2021 · MCQ
  • The instantaneous velocity of a particle moving in a straight line is given as V=αt+βt2, where α and β are constants. The distance travelled by the particle between 1s and 2s is :2021 · MCQ