Kinematics Question 334
Question: A bullet fired into a wooden block loses half of it’s velocity after penetrating 40 cm. It comes to rest after penetrating a further distance of
Options:
A) $ \frac{22}{3}cm $
B) $ \frac{40}{3}cm $
C) $ \frac{20}{3}cm $
D) $ \frac{22}{5}cm $
Show Answer
Answer:
Correct Answer: B
Solution:
For first part of penetration, by equation of motion $ ( \frac{u}{2} )-{{( u )}^{2}}=2aS\text{ or a = -}\frac{3u^{2}}{8S}….(i) $ For latter part of penetration $ {{( 0 )}^{2}}-{{( \frac{u}{2} )}^{2}}=2aS\text{ or a=-}\frac{3u^{2}}{8S}….( i ) $
$ S’\text{=}\frac{S}{3}\text{or S }’\text{ =}\frac{40}{3}cm $
