Calculate the kinetic energy of a tractor crawler belt of mass `m` if the tractor moves with a velocity `v`. There is no slipping. Neglect the size of the wheels.

Explanation

Since the lower part of the belt is in contact with the rigid floor, velocity of this part becomes zero. The crawler moves with velocity v, hence the velocity of upper part of the belt becomes `2v` by the rolling condition and kinetic energy of upper part `=1/2(m/2)(2v)^2=mv^2`, which is also the sought kinetic energy, assuming that the length of the belt is much larger than the radius of the wheels.