Answer:
60J
Explanation:
friction is the opposition to the motion of an object. Before a body can be set in motion, part of the energy or work-done must be used to overcome friction.
While kinetic energy is the energy associated with a body due to its motion.
Since friction tends to oppose the motion of a body,when a body start to move, some of the energy applied to the body to cause its motion is converted to heat due to friction.
Hence if a work-done of 100J is applied to a body that requires 40J of the work to overcome friction, the total change in the kinetic energy can be expressed as
[tex]K.E=100J-40J\\K.E=60J\\[/tex]
