Question

A ball is dropped from rest from a height. If it takes 0.2s to cross the last 6m before hitting
he ground, find the height from which it was dropped.(g=10m/s²)​

Answer 1

Explanation:

the last distance travelled by the system = 6m.

time=0.2s

Initial Velocity=?

a=g=10m/s²

s=ut+1/2at²

6=u(0.2)+1/2×10×0.2×0.2

6=0.2 u + 5×0.04

6-5×0.04/0.2=u

u=29m/s

for distance x, u=0m/s

v=29m/s (because initial velocity will be the final)

a=g=10m/s²

s=v²-u²/2a

=29²-0²/2×10

s=42.05m

Total distance = 42.05+6

=48.05 m