Using a pulley, you apply a force of 10 Newtons to life an object that weighs 100 Newtons. What is the mechanical advantage of that pulley?

10

Explanation:

Assuming this is AMA you are talking about all you have to do is use the formula Actual mechanical advantage=Output force/Input force

Input is 10 (the force you are putting in) and the output (what you are lifting) is 100

if you already have the answer to (a), then just work out how many periods there are in 1 minute, and that's the answer to (c).

tube or goog with be a great resource to with that question