Question

A free falling body reaches the ground after 4s What is the height which it reaches?

Answer 1

Answer:

as the body is falling freely so initial velocity is zero then by using second equation of motion,

S=gt²

S=(9.8)(4)²

S=156.8 m

Answer 2

Given: A freely falling body reaches ground after 4 s.

To find: Height which it reaches

Explanation: Since the time taken to go up is equal to time taken in coming down, the time that the body took in coming down is 4/2= 2 s

At highest point, velocity (u)= 0

Using kinematic formula, Height= 1/2at^ 2

= 1/2* 10* 4

= 20 m

Also, the height that it comes down is equal to the maximum height that it reaches during its upward motion.

Therefore, the height that the body reaches is 20 m.