# Non-Physics Major Needs Physics Help!

Hi, I'm a new member, and my problem is that I'm new to physics. I'm a non-physics major, taking a physics course to fill in a science credit. This is the most basic of basic courses. I'm reviewing for a test and will post questions accordingly.

If you want symbols, variables, and data, you'll have to be patient with me. Because I do not understand any of this.

1. What is the difference between a compound lever and a multiple lever? I was told a multiple lever is made up of loads and efforts where the load of one lever becomes the effort of another lever. But I don't understand how that would work in a practical setting, and even if it did, how is that different from a compound lever? What is a compund lever? I must be able to give real-world examples of each.

2. Assume that a wheel is a type of lever, with the axle being the fulcrum. If you put the effort on the axel, does it become a third class lever, moving the outer portion of the wheel? What about when you put the effort on the outer part of the wheel? Is that a second class lever? My professor insists that we think of the wheel-and-axel as a lever. It makes very little sense to me. And for each class of...wheel? We have to identify if we gain a Mechanical Advantage (MA) or a Speed Advantage (SA).

3. How does one determine the mechanical advantage of a pulley system? My teacher says it has to do with how many ropes are at work. "The Ideal Mechanical Advantage (IMA) of a pulley system is equal to the number of supporting ropes."

If you have a long rope, it is divided among the pulleys into smaller ropes. But what's the different between a change in direction, and an actual rope?

I have more questions. Lots of them. My test is on Tuesday and I'm trying to get as much help as I can.

## Answers and Replies

LowlyPion
Homework Helper
Hi, I'm a new member, and my problem is that I'm new to physics. I'm a non-physics major, taking a physics course to fill in a science credit. This is the most basic of basic courses. I'm reviewing for a test and will post questions accordingly.

If you want symbols, variables, and data, you'll have to be patient with me. Because I do not understand any of this.

1. What is the difference between a compound lever and a multiple lever? I was told a multiple lever is made up of loads and efforts where the load of one lever becomes the effort of another lever. But I don't understand how that would work in a practical setting, and even if it did, how is that different from a compound lever? What is a compund lever? I must be able to give real-world examples of each.

2. Assume that a wheel is a type of lever, with the axle being the fulcrum. If you put the effort on the axel, does it become a third class lever, moving the outer portion of the wheel? What about when you put the effort on the outer part of the wheel? Is that a second class lever? My professor insists that we think of the wheel-and-axel as a lever. It makes very little sense to me. And for each class of...wheel? We have to identify if we gain a Mechanical Advantage (MA) or a Speed Advantage (SA).

3. How does one determine the mechanical advantage of a pulley system? My teacher says it has to do with how many ropes are at work. "The Ideal Mechanical Advantage (IMA) of a pulley system is equal to the number of supporting ropes."

If you have a long rope, it is divided among the pulleys into smaller ropes. But what's the different between a change in direction, and an actual rope?

I have more questions. Lots of them. My test is on Tuesday and I'm trying to get as much help as I can.

Welcome to PF.

Perhaps this will help?
http://en.wikipedia.org/wiki/Pulley#Types_of_systems