Question

A stone is released from a hot air balloon which is rising steadily with a velocity of ${4ms}^{-1}$. The velocity of the stone at the end of 3 s after it is released is _____ ${ms}^{-1}$

• A. 29.4
• B. 25.4
• C. 32.5
• D. 62.7

Answer 1

The correct option is B 25.4

Let the upward direction to be negative.

Initial velocity of stone $u=-4m/s$

Acceleration of the stone $a=g=9.8m/s^2$

Velocity of stone $v=u+at$

$\therefore$ $v=-4+9.8\times 3=25.4m/s$