Question

How do machines make work easier if they do not decrease the amount of work you need to do?

Answer 1

Machines decrease power needed to perform work

Explanation:

Machines do not change the work done on an object, but they do decrease the power needed to perform the work.

Work is given by `W = DeltaE = Fd`
where `DeltaE` is change in energy, `F` is a force applied, and `d` is a parallel distance to the force

Power is defined as work over time, or
`P = (DeltaE)/(Deltat)`

Machines such as pulleys, inclined planes, or screws perform the same work on a system over a greater amount of time. We can see in the power equation that as `Deltat` increases, power required decreases. This is where the usefulness of machines comes in, they reduce the power needed to perform work.