Question

A tennis ball being dropped from a certain height reached the ground after 4 sec. If no additional force was applied except gravitational force determine the height from which ball was dropped

Answer 1

Answer:

Uniformly accelerated otion.

So for last 6m distance travelled

As we know  

S=ut+21​at2

Given :-  

S=6m

u=?

t=0.2 sec

a=g=9.8m/s2

s=ut+21​at2→6=4(0.2)+4.9×0.01

u=29m/s

For distance x,u=0,v=29m/s

a=g=9.8m/s2

s=2av2−u2​⇒2×9.8292−02​⇒42.05

Total distance =42.05+6

                       =48m

Step-by-step explanation: