A ball of mass 0.5 kg slows down from a speed of 5 m/s to that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.

Mass, m = 0.5 kg

Initial velocity (v1) = 5m/s


Final velocity (v2) = 3m/s


Initial K.E = 1/2m (v1)2


=1/2 × 0.5 × (5)2


Final K.E = 1/2 (mv2)2


=1/2 × 0.5 × (3)2


Work done = Change in K.E


= 2.25 - 6.25


= - 4 J


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