Bill’s job is to lift bags of flour and place them in the back of a truck, which is parked next to him. Sally is loading the same bags of flour into a similar truck that is located 10 m away. Sally wants a raise because she says she is doing more work than Bill. Does the physics definition of work support her claim?
Attempt: By the definition Work is Force multiplied by the Displacement in the direction of the force. Sally does the same amount of Work when she lifts the bag. But, when she cares the bag for 10 m to the truck there is no force exerted on the bag in the direction of the truck. Therefore, she does the same amount of Work. Is my reasoning correct? Why the Force exerted in the direction of the truck is zero?