Question

machines help us to do work. a machine is a device that makes work easier. it does this by changing the direction of the force, changing the amount of force, or changing the distance over which the force is being spread. work is defined mathematically as force times distance. using a pulley and rope system to move objects changes the direction of the force from pulling the rope straight up to using gravity as an advantage to pull the rope down. how does the pulley on the well in the picture make work easier when pulling up a bucket of water? it increases the amount of force. it adds weight to the bucket. it changes the direction of the force.

Explanation:

The text mentions that machines make work easier by changing force direction, amount, or distance. The pulley - rope system example in the text specifically states changing force direction (from pulling up to using gravity to pull down). The first option (increasing force) is not supported by the text's pulley example. The second option (adding weight) is irrelevant. The third option aligns with the text's description of how the pulley - rope system (like the well pulley) functions.

Answer:

It changes the direction of the force.