Question

A ball is thrown horizontally from the top of a tower $40$m high. The ball strikes the ground at a point $80$m from the bottom of the tower. Find the angle that the velocity vector makes with the horizontal just before the ball hits the ground.

• A. $45m/s$
• B. $90m/s$
• C. $37m/s$
• D. $53m/s$

Answer 1

Answer: (A)

$45m/s$

initial vertical velocity v is 0

distance covered in the vertical direction is 40 m

$s=ut+\frac{1}{2}{at}^2$

$40=\frac{1}{2}\times 10\times t^2$

$=t=2\sqrt{2}seconds$

horizontal velocity is u

$ut=90=u=902\sqrt{2}=45\frac{m}{s}$