- A3h
- B
- Ch
- Dh
View written solutionFree
Correct answer: A
- Initial fall
The object is dropped from height . So the first distance covered is
Just before hitting the ground, its kinetic energy is
- Energy loss at each collision
It loses of its kinetic energy at every hit. So after the first collision, remaining kinetic energy is
This kinetic energy converts into potential energy during the upward motion:
So after first bounce, it rises to height and then falls back the same distance .
- Subsequent bounces
Each time the object hits the ground, its kinetic energy becomes half of what it had just before collision. Hence each rebound height is half of the previous height.
So the heights reached after successive bounces are:
- Total distance covered
Total distance consists of:
- first downward fall:
- then for each bounce, upward and downward travel of twice the rebound height
Therefore,
The series inside brackets is a geometric progression:
Thus,
- Check options
- A: ✅
- B: ❌
- C: ❌
- D: ❌
Hence the correct answer is
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