You observe someone pulling a block of mass 43 kg across a low-friction surface. While they pull a distance of 3 m in the direction of motion, the speed of the block changes from 5 m/s to 7 m/s....

You observe someone pulling a block of mass 43 kg across a low-friction surface. While they pull a distance of 3 m in the

direction of motion, the speed of the block changes from 5 m/s to 7 m/s. Calculate the magnitude of the force exerted by the

person on the block. What was the change in internal energy (chemical energy plus thermal energy) of the person pulling the

block?