What simple machine helps us to lift things?

Answer 1

It depends completely on how you use it. For any given simple machine, you can easily calculate the efficiency ratio, which is applied force/resultant force. Your question has no general answer -- for example, a lever has a vastly different efficiency ratio depending on where you place the fulcrum. The best simple machine in any given situation depends on that situation. There's really no better answer than that. You probably don't want to set up a pully system to get a fridge onto a truck, but you would want one to get a pipe to the top of a skyscraper. One thing to keep in mind is that levers and inclined planes are generally easier to set up and use than other simple machines.

Answer 2

a pulley system ( a rope swung over a wheel that's secured at celing height usually. One end of the rope is you pulling and the other end is tied to what you are trying to lift.

or

a lever (as in give me a lever and I'll move the world)

Answer 3

A pulley would be best for lifting a heavy object higher.