Barney and Fred are moving again. They slide large crates down the ramp from the truck to the ground. Tocontrol a crate and keep it sliding at a constant speed, Barney backs down the ramp in front of the cratewhile pushing upward on it. During its trip to the bottom, is the thermal energy created in the ramp and thecrate greater than, less than, or equal to the crate’s loss of gravitational potential energy? Explain.