A boa box of mass 10kg is pulled along a rough floor with a force of 100N. the frictional force acting on the box is a constant 20N. What is the change in the kinetic energy of the box?

1 answer

the box is constantly accelerating

the net force is ... 100 N - 20 N = 80 N

f = m a ... acceleration = force / mass = 80 N / 10 kg = 8 m/s^2

the K.E. is increasing