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.

Given,

Mass = 0.5 kg

Initial velocity = 10 m / s

Final velocity of the ball = 6 m / s

Kinetic energy = $\dfrac{1}{2}$ × mass × (velocity)²

Substituting the values in the equation we get,

Initial KE = $\dfrac{1}{2}$ x 0.5 x 10²

= $\dfrac{1}{2}$ x 0.5 x 100

= 0.5 x 50

= 25 J

Final KE = $\dfrac{1}{2}$ x 0.5 x 6²

= $\dfrac{1}{2}$ x 0.5 x 36

= 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.