Question

A balloon starts rising from the ground with an acceleration of $1.25m{s}^{-2}$. After 8 s, a stone is released from the balloon. The stone will

• A. Cover a distance of 40 m
• B. Have a displacement of 40 m
• C. Reach the ground in 4 s
• D. Begin to move down just after being released.

Answer 1

The correct option is B Have a displacement of 40 m

Let the upward direction be positive.

Initial velocity of balloon $u=0m/s$

Acceleration $a=1.25m/s^2$

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

So, height attained by balloon in 8 seconds, $H=0+\frac{1}{2}\times 1.25\times 8^2=40m$

So, the displacement of the stone is $40m$.