Laws Of Motion Question 294
Question: A stone is dropped from a height h. It hits the ground with a certain momentum P. If the same stone is dropped from a height 100% more than the previous height, the momentum when it hits the ground will change by:
Options:
A) 68%
B) 41%
C) 200%
D) 100%
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Momentum $ P=mv=m\sqrt{2gh} $
$ ( \therefore v^{2}=u^{2}+2gh;\text{ Here }u=0 ) $
When stone hits the ground momentum $ P=m\sqrt{2gh} $
When same stone dropped from 2h (100% of initial) then momentum $ {P}’=m\sqrt{2g(2h)}=\sqrt{2}P $
Which is changed by 41 % of initial.
