# How long would a lever have to be to compete with a hydroelectric dam?

• Lever Enthusiast

#### Lever Enthusiast

TL;DR Summary
How long would a lever have to be for for a on the effort arm to generate the equivalent energy of a single hydroelectric dam generator? State weight/force in kg.

First scenario: Assume no friction.
Second scenario: Assume friction.

Bonus question: What would be the best compound lever you can think of to do the same work but with less distance to move the lever?

I think a compound lever and gear system could allow the effort and resistance sources to be on the same level.
How long would a lever have to be for the weight on the effort arm to generate the equivalent energy of a single hydroelectric dam generator? State weight/force in kg.

My ponderings:

The weight could be anything, would be interesting to use water weight from a passive air water condenser in a high up location, or snow melted under a magnifying glass, and placing this on the effort arm and producing a large amount of force and energy below on the resistance arm. I wondered this question because the outsized electrical energy could be interesting to investigate. If the resistance arm is one meter in length and the effort arm is 1000 meters long (less than 1/8th the height of Mount Everest) and 10 kilograms of effort, this could generate 10,000 kilograms worth of force. The lever would be balanced in such a way that the lever's natural balance, without any force applied on the effort arm and resistance arm, is that the effort arm stays up and resistance arm stays down, therefor it has a natural return. The weight water goes down, dumps out at the bottom, the lever returns back up to be filled again.

First scenario: Assume no friction.
Second scenario: Assume friction.

Bonus question: What would be the best compound lever you can think of to do the same work but with less distance?

I think a compound lever and gear system could allow the effort and resistance sources to be on the same level.

A lever does not increase the energy, it changes the ratio of distance to force. The product of distance and force is work done = energy.

A 1 kg mass will produce a force due to gravity of 9.8 Newtons.

A hydroelectric plant generates energy at a rate measured in joules per second = watts.

• Lnewqban and russ_watters
I understand that levers don't create energy, they transfers energy from distance into force. But wouldn't this kinetic force be able to be transferred into torque energy in a rotor, such as a salient pole rotor? For example, at the end of the resistance arm of the lever you attach a straight spur gear and make contact with a small spur gear which is attached to an axel which is attached to a larger diameter salient pole rotor. As long as the salient pole rotor weight/torque requirement does not exceed the weight/force of the resistance arm, the rotor should spin and generate electricity. It's basically the same concept of a hydroelectric dam which uses water weight at a distance exerted by gravity, except a lever uses a tiny bit of water. So I was just wondering, what kind of size lever would be needed to generate electricity from a typical hydroelectric salient pole rotor?

Perhaps I'm misunderstanding the physics/mechanics of the this system?

I understand that levers don't create energy, they transfers energy from distance into force. But wouldn't this kinetic force be able to be transferred into torque energy in a rotor, such as a salient pole rotor? For example, at the end of the resistance arm of the lever you attach a straight spur gear and make contact with a small spur gear which is attached to an axel which is attached to a larger diameter salient pole rotor. As long as the salient pole rotor weight/torque requirement does not exceed the weight/force of the resistance arm, the rotor should spin and generate electricity. It's basically the same concept of a hydroelectric dam which uses water weight at a distance exerted by gravity, except a lever uses a tiny bit of water. So I was just wondering, what kind of size lever would be needed to generate electricity from a typical hydroelectric salient pole rotor?

Perhaps I'm misunderstanding the physics/mechanics of the this system?
This is complete nonsense. I can't tell yet from your profile page if you are just a young person who is clueless about science so far, or if you are tolling us. Based on your registration e-mail address (which as a Mentor I can see), I think it is likely that you are trolling us.

This thread will stay closed. Reply to my warning PM if you want to discuss this more. If you are just a clueless kid early in your education, please keep paying attention in class when the concepts of Force, Energy, Power and Work are discussed. The Relevant Equations for such calculations are very straightforward at your level.

• hutchphd and Bystander
I know this is locked (maybe temporarily?), but I can offer:
Perhaps I'm misunderstanding the physics/mechanics of the this system?
Yes, specifically, you're misunderstanding the concept and application of "energy":
I understand that levers don't create energy, they transfers energy from distance into force. But wouldn't this kinetic force be able to be transferred into torque energy in a rotor, such as a salient pole rotor?
"kinetic force" and "torque energy" aren't things that exist. There's force, kinetic energy and torque, but the way you've mixed and matched the terms just makes gibberish. Look at the equations, and recognize that the definitions of the terms in those equations have very specific meanings:
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