Question

a ball is dropped from a height h from rest.the ball travels (h/2) in last 1.0s the total time taken to the ball hit the ground is...
Ans 3.41s

Answer 1

$t-t_0=1\to \sqrt{\frac{2h}{g}}-\sqrt{\frac{2h/2}{g}}=1\to$

$\sqrt h(\sqrt{\frac{2}{g}}-\sqrt{\frac{1}{g}})=1\to$

$h=\frac{1}{(\sqrt{\frac{2}{g}}-\sqrt{\frac{1}{g}})^2}=57.197(m)$

$t=\sqrt{\frac{2h}{g}}=\sqrt{\frac{2\cdot 57.197}{9.81}}=3.41(s)$