question_answer

A ball is projected horizontally with a velocity of 5 m/s from the top of a building 19.6 m high. flow long will the ball take to hit the ground?

A)  \[\sqrt{2}s\]                                     

B)  2s

C)  \[\sqrt{3}s\]                                     

D)  3s

Correct Answer: A

Solution :

                The time taken to hit the ground is given by                 \[T=\sqrt{\frac{2H}{g}}\]                 \[=\sqrt{\frac{2\times 19.6}{9.8}}=2s\]