Question

A ball is released from the top of a tower of height $h$. It takes time $T$ to reach the ground. What is the position of the ball (from the ground after time $T/3$)?

• A. $h/9$
• B. $7h/9$
• C. $8h/9$
• D. $17h/18$

Answer 1

The correct option is C $8h/9$

As the ball is released from rest initially ⟹ u = 0
By using second equation of motion we have, $h=\frac{1}{2}g{t}^2=\frac{1}{2}g{T}^2$
When, $t=\frac{T}{3}$
The distance fallen $=\frac{1}{2}g{\left(\frac{T}{3}\right)}^2=\frac{h}{9}$
So position of the ball from the ground
$=h-\frac{h}{9}=\frac{8h}{9}m$