Question

A ball of mass 0.5 kg slows down from a speed of 10ms^-1 to that of 6ms^-1. Calculate the change in kinetic energy of the ball.

April 18, 2024

Answer

Mass = 0.5 kg

Initial velocity = 10 m / s

Final velocity of the ball = 6 m / s

KE = $1\over 2$ × m × v²

= $1\over 2$ × 0.5 × 10²

= 0.5 × 50

= 25 J

Final KE = $1\over 2$ × 0.5 × 6²

= 0.5 x 18

= 9 J

So, change in the kinetic energy of the ball = 9 J – 25 J = -16J

Hence, there is a decrease in the kinetic energy of the ball by 16J.

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