Question

A ball of mass 0.5 kg slows down from a speed of 5 m s-1 to that of 3 m s-1.Calculate the change in kinetic energy of the ball.

Answer 1

change in kinetic energy => 1/2*m*(v^2-u^2)
=>1/2*0.5*(3*3-5*5)
=>1/2*0.5*(-16) =>0.5*(-8) => -4J

Answer 2

Change in ke =1/2m(v^2-u^2)
1/2*0.5*-16=-4 J