Question

A ball is released from the top of a tower of height h metres. It takes T seconds to reach the ground.
What is the position of the ball in T/3 seconds?

• A. h/9 metre from the ground
• B. 7h/9 metre from the ground
• C. 8h/9 metre from the ground
• D. 17h/18 metre from the ground

Answer 1

The correct option is C 8h/9 metre from the ground

It takes T seconds to reach the ground from a tower of height 'h'.$0\ast T+\frac{1}{2}g{T}^2=h$$T=\sqrt{\frac{2h}{g}}$Position of ball at time $T/3$$=0\ast t+\frac{1}{2}g{t}^2$$=\frac{1}{2}\times g\times \frac{2h}{9g}=\frac{h}{9}$ from the top of tower.OR $\frac{8h}{9}$ from the ground