1.

A bullet 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»

Mass of ball = 0.5kg

Initial velocity = 5m/s

Initial kinetic energy = 1/2 × mass x (velocity)2 

= 1/2 ×0.5 ×(5)2 

= 1/2 ×0.5 ×25=6.25J

Final velocity of the ball = 3m/s

Final kinetic energy of the ball =1/2 × mass x (velocity)2 

= 12 × 0.5 x (3)2 

= 12 ×0.5 x 9 = 2.25J

Change in the kinetic energy of the ball = 2.25 J − 6.25J = − 4J

There is a decrease in the kinetic energy of the ball



Discussion

No Comment Found

Related InterviewSolutions