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

• Lever Enthusiast
In summary: No, kinetic energy is not able to be transferred into torque energy in a rotor. Torque is a rotational force that resists the motion of the object that is undergoing it.
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?

Lever Enthusiast said:
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:
Lever Enthusiast said:
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:

And above all else, always remember that conservation of energy rules everything we do. If you think you've found a way to generate more energy than you put in, go back and reared that.
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.
In this description the gear train is superfluous. Again, conservation of energy tells us that whatever the energy input is to the "resistance arm", that's the maximum energy output at the generator. This value is the same whether there's a gear train in the middle or not.
It's basically the same concept of a hydroelectric dam which uses water weight at a distance exerted by gravity...
It's not. You're neglecting the flow of the water. The height gives you a large force on the generator turbine, but to use that to generate a lot of electricity you need a massive flow rate of water.

Lnewqban and berkeman

## 1. How does a lever compare to a hydroelectric dam in terms of power generation?

A lever is a simple machine that uses a fulcrum and a force to lift or move objects. A hydroelectric dam, on the other hand, uses the force of water to generate electricity. In terms of power generation, a hydroelectric dam is much more efficient and powerful than a lever.

## 2. What factors determine the length of a lever needed to compete with a hydroelectric dam?

The length of a lever needed to compete with a hydroelectric dam depends on several factors, including the force applied, the distance from the fulcrum to the point of force application, and the weight of the object being lifted or moved. A longer lever allows for a greater mechanical advantage, but it also requires more force to be applied.

## 3. Can a lever ever be as efficient as a hydroelectric dam?

No, a lever can never be as efficient as a hydroelectric dam. This is because a lever relies on physical force and the laws of motion, whereas a hydroelectric dam uses the power of water, which is a much more powerful and consistent force.

## 4. Is there a specific formula for calculating the length of a lever needed to compete with a hydroelectric dam?

There is no specific formula for calculating the length of a lever needed to compete with a hydroelectric dam. The length of the lever will vary depending on the specific circumstances and factors involved, and it may not be possible for a lever to compete with a hydroelectric dam in terms of power generation.

## 5. Are there any real-world examples of a lever competing with a hydroelectric dam?

No, there are no known examples of a lever competing with a hydroelectric dam. As mentioned before, a lever is not as efficient or powerful as a hydroelectric dam, so it is unlikely that a lever would be able to compete with a hydroelectric dam in any real-world scenario.

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