A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 m s-2, with what velocity will it strike the ground? After what time will it strike the ground?
Given, initial velocity of ball, u=0 Final velocity of ball, v=? Distance through which the balls falls, s=20m Acceleration a=10ms−2 Time of fall, t=? We know v2−u2=2as or v2−0=2×10×20=400 or v=20ms−1 Now using v=u+at we have 20=0+10×t or t=2s
