Question

A body is projected vertically down with a velocity of 4 ms-1

from the top of a tower. If it reaches the
ground in 2 sec. What is the height of the lower and velocity with which it reaches the ground?​

Answer 1

Explanation:

From second equation of motion, s=ut+at2/2

Assume upward direction to be positive. 

u=4.9 m/s, t=3 sec, a=−9.8 m/s2

s=4.9×3−9.8×32/2

s=−29.4 m

Height = 29.4 m