A man throws balls 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 balls are in the sky at any time?
Interval of ball thrown = 2 sec If we want that minimum three balls remain in air then time of flight of first ball must be greater than 4sec. T is greater than 4 sec 2u/g is greater than 4sec = u is greater than 19.6 m/s
