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.



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