Question

Two people each do 100 joules of work by pushing a crate to the right. During this process, 50 joules of heat is generated from the
friction between the floor and the crate. How much energy is gained by the crate during this process?

Answer 1

Because of friction, net work on the crate is less. ∆KE = Net work = net force x distance = (100 N – 70 N)(10 m) = 300 J.