Kinetic energy

A trolley of mass 2 kg moves with a uniform speed of 4 ms-1 along a horizontal table. A

lump of plasticine having the same mass as the trolley is dropped from a height slightly

above the trolley and sticks to it. Find the total loss in kinetic energy.

Need steps to explain ! thx !


mu + MU = mv + MV

2(4) + 0 = (2 + 2)V

V = 2 ms-1

the loss in K.E.

= [(1/2)mu^2 - (1/2)(m + M)V^2] J

= (16 - 8)J

= 8J