A man throws ball with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two ball are in the sky at any time (Given `g=10(m)/(2^2)`)

Options

A. At least `0.8 m//s`
B. Any speed less than `19.6 m//s`
C. Only with speed `19.6 m//s`
D. More than `19.6 m//s`

Answer

D

Explanation

If balls are thrown with speed `19.6 m//s`, it will return to man after `4 s`. Third ball will be thrown, when the first ball comes to man. To keep more than two balls, balls should be thrown with speed more than `19.6 m//s`.