Question

Q.):- A stone dropped from the top of the tower touches the ground in 4 sec. The height of the tower is about
a) 80 m b) 40 m c) 20 m d) 160 m

Answer 1

Dear Student,
$$\begin{gathered} Height=\frac{1}{2}g{t}^2 \\ =\frac{1}{2}\times 10\times 4^2=20m \end{gathered}$$
Regards