How can we run out of energy if energy cannot be created or destroyed?

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.

Astudent pushes a 40-n block across the floor for a distance of 10 m. how much work was applied to move the block? a. 4 j b. 40 j c. 400 j d. 4000 j

Suppose you hit your hand against the edge of table. using newton’s third law of motion why does my hand hurt? explain