Kinematics Question 215
Question: A stone is shot straight upward with a speed of 20 m/sec from a tower 200 m high. The speed with which it strikes the ground it’s approximately [AMU (Engg.) 1999]
Options:
A) 60 m/sec
B) 65 m/sec
C) 70 m/sec
D) 75 m/sec
Show Answer
Answer:
Correct Answer: B
Solution:
Speed of stone in a vertically upward direction is 20m/s. So for vertical downward motion we will consider $ u=-20\ m/s $
$ v^{2}=u^{2}+2gh={{(-20)}^{2}}+2\times 9.8\times 200=4320\ m/s $ $ v\tilde{-}65m/s $ .
