Reducing force in pulleys

[jgalt42]

What do you do to reduce the force you apply in a pulley? Add more pulleys?

 

[G1SG2]

What do you do to reduce the force you apply in a pulley? Add more pulleys?

More pulleys allow you to distribute the force necessary to lift an object. Like if you had to lift a 40 N object, instead of having one pulley, you can have four pulleys with tensions of 10 N each in the ropes.

 

[jgalt42]

So is the force always going to be the same in a pulley machine? Do we only take into account pulleys that directly act on the weight you're trying to pull?

 

[loveoforganic]

http://www.youtube.com/watch?v=TlPWy7qW7oM

Good vid!

 

[G1SG2]

So is the force always going to be the same in a pulley machine? Do we only take into account pulleys that directly act on the weight you're trying to pull?

No, the force decreases on each pulley as the number of pulleys increase. Like in my 40 N example, the 4 pulleys each have a tension of 10 N in their ropes. However, if you only had two pulleys, they each would have 20 N tensions in their ropes. Take all the pulleys that are contributing to lifting into account.