Question

A ball is dropped from a height if it takes 0.200 second to cross the last 6.00 M before hitting the ground find the height from which it was dropped .take 10 M per second square

Answer 1

Solution :

For last 6m distance travelled , s=6m

time=0.2s

initial velocity=?

a=g=9.8m/s2

s=ut+1/2at²
=6=u(0.2)+1/2 x 9.8 x0.2x0.2
6=0.2 u + 4.9 x 0.04

u=5.8/0.2
u=29m/s

For distance x, u=0m/s

v=29m/s [ because initial velocity will be final]

a=g=9.8m/s2

s= v²-u²/2a
=29²-0²/2x9.8
=29x29/19.6
s=42.5m

Total distance=42.5 +6=48.5 m