Question

A body dropped from the top of a tower reaches the ground in 4 s. The height of the tower could be :

• A. 39.2 m
• B. 44.1 m
• C. 58.8 m
• D. 78.4 m

Answer 1

The correct option is D 78.4 m

Let, $h$ be the height of tower.

Using formula, $S=ut+\frac{1}{2}a{t}^2$, $h=0\left(4\right)+0.5\left(9.8\right)(4{)}^2=78.4m$ where $a=g=9.8m/s^2$