Question

An object is projected vertically up with 40 m/s from the ground. Its velocity after 6 sec of projection is (g = 10 2 / ms)

Answer 1

U= 40m/sec, A point of height at which object has no velocity means V=0 then time, V=U-gt , 40=0-10×t , then t is 4 sec( here - sign is indicated the direction of g ), it reaches maximum height in 4 sec then after this it moved to ground with initial velocity is zero and after 2 second it's velocity is ,V=U+gt , V=0+10×2 , V= 20m/sec is your answer