2007-01-03 18:44:48 · 4 answers · asked by felicia 1 in Science & Mathematics ➔ Engineering
You know a pulley system? It's that little thing that you put rope on, and when you pull on one end of the rope the thing on the other end raises it's level.
lol, sorry, that wasn't the greatest answer, so....
1.a wheel, with a grooved rim for carrying a line, that turns in a frame or block and serves to change the direction of or to transmit force, as when one end of the line is pulled to raise a weight at the other end: one of the simple machines.
2.a combination of such wheels in a block, or of such wheels or blocks in a tackle, to increase the force applied.
3.a wheel driven by or driving a belt or the like, used to deliver force to a machine, another belt, etc., at a certain speed and torque.
2007-01-03 18:54:57 · answer #1 · answered by emmathefirst 1 · 0⤊ 0⤋
A simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope.
A pulley is a wheel with a groove along its edge, also called a sheave, for holding a rope or cable.
Use: Pulleys are usually used in sets designed to reduce the amount of force needed to lift a load. However, the same amount of work is necessary for the load to reach the same height as it would without the pulleys.
The magnitude of the force is reduced, but it must act through a longer distance.
The effort needed to pull a load up is roughly the weight of the load divided by the number of wheels.
The more wheels there are, the less efficient a system is, because of more friction between the rope and the wheels.
2007-01-03 19:00:32 · answer #2 · answered by Amit B 2 · 2⤊ 0⤋
Normally they are grooved wheels over which a rope or cable can be passed. They are usually partly enclosed but don't have to be.
2007-01-03 18:54:48 · answer #3 · answered by Warren D 7 · 0⤊ 0⤋
i have no clue
2007-01-03 18:46:52 · answer #4 · answered by Anonymous · 0⤊ 1⤋