Question

a body starts from the rest and falls through a height of 19.6m the time taken to fall through the last 4.9m of its fall is

Answer 1

for first 14.7 m (i.e. 19.6 - 4.9) ,,we have u=0 , s= 14.7 , a= g=9.8 , t= ?
use newtons 2nd eqn here..
now for total time,,s=19.6 , a= g, u= 0 , t=?
again use newton's second eqn
therefore,,req ans = total time - time for first 14.7 m ..