Determine the amount of kinetic energy lost when a car of mass 900 kg slows from 70 km/h to 50 km/h. What is the constant force acting on a body of mass 8 kg if its velocity increases from 4 m/s to 6...

Determine the amount of kinetic energy lost when a car of mass 900 kg slows from 70 km/h to 50 km/h.

What is the constant force acting on a body of mass 8 kg if its velocity increases from 4 m/s to 6 m/s while it moves through a distance in the direction of the force of 5 m?