A man in a balloon rising vertically with acceleration 4.9 m s⁻² releases a ball 2 s after the balloon starts from the ground. The greatest height above the ground reached by the ball is (g=9.8 m s⁻²):
Options

Question

A man in a balloon rising vertically with acceleration 4.9 m s⁻² releases a ball 2 s after the balloon starts from the ground. The greatest height above the ground reached by the ball is (g=9.8 m s⁻²):

Options

G1 Physics · Accepted Answer

After 2 s the balloon is at h=(1/2)(4.9)(2²)=9.8 m and has upward speed 9.8 m s⁻¹. The released ball rises further by v²/(2g)=4.9 m. Maximum height =14.7 m. Hence option A.