an 875kg car speed from 22m/s to 44m/s while pushing another car. what work was in changing the car's speed?

Work done = energy change

So inorder to calculate the work done in change in velocity of the car you need to calculate the difference of kinetic energy in each state of car motion.

To calculate kinetic energy (K. E.) of a car of mass m and velocity v,

K. E. = ½mv²

Initially the car has a speed of 22 m/s,

So we get,

K. E. = ½m * (22) ²

After the push car has a velocity of 44 m/s. So now car has a energy of,

K. E. = ½m * (44) ²

So difference in energy is,

Difference in K. E. = ½*875 * (44²-22²)

= 635250 J

= Energy change