38. A 4 kg object is moving horizontally with a speed of 5 m/s. To increase its speed to 10 m/s, the amount of net work required to be done on this object is: A.150 J B.100 J C.50 J D.75 J
Option A Solution: m=4 kg u=5 m/s v=10 m/s according to work energy theorem w=1/2*m*(v2-u2) w=1/2*4*(102-52) w=1/2*4*(100-25) w=2×75 w=150 J
