Question

A freely falling body covers half of its journey from the top of a tower in $0.5s$. What is the height of the tower?

• A. $4.9m$
• B. $2.45m$
• C. $9.8m$
• D. $9m$

Answer 1

The correct option is B $2.45m$

Let the height of tower be $H$.

Thus distance covered in $0.5s$ is $H/2$.

Initial speed of the body $u=0$

Acceleration due to gravity $g=9.8m/s^2$

Using $S=ut+\frac{1}{2}g{t}^2$

where $t=0.5s$ and $S=H/2$

$\therefore$ $\frac{H}{2}=0+\frac{9.8}{2}\times (0.5{)}^2=1.225$

$⟹H=2\times 1.225=2.45m$