Mechanical Energy and Electricity

In summary, mechanical energy and electricity are closely related concepts in the study of physics. Mechanical energy is the energy an object possesses due to its motion or position, while electricity is the flow of electric charge. Mechanical energy can be converted into electrical energy through generators and turbines, while electrical energy can be converted into mechanical energy through motors and engines. The conservation of energy principle applies to both mechanical and electrical energy, as energy cannot be created or destroyed, only transformed. Understanding the relationship between mechanical energy and electricity is crucial in many practical applications, such as power generation and transportation.
  • #1
lorenzotr
2
0
Hi, my question is rather simple.
Supose you can generate 10 000N, by any means, such as pedaling a bycicle.
What calculations should you make to know how much electricity would 10 000 N of force will generate.
-Assuming a generator efficiency of 100%, leaving friction aside, etc.
An example would be, how much electricity will i produce by pulling a string attached to the rotor of the generator, and the total force that will exert during 1 hour will be 10,000 N?
If you also please tell me how i can convert the result to kWh?

I have a very basic understanding of physics, and if you think i would not be able to understand your answer at this stage, may you please tell me what prior reading i should make before asking this question, or if you may give me a very detailed answer to my question.

By the way, this is an amazing forum, and all its participants are really making an effort to help others. Thank you to you all.
 
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  • #2
Welcome to PF.

Newtons are a force, not an energy (and there is no "total force" over time) and so there is no direct relationship between the two. However, given the mechanical advantage required to get a person to generate 10,000 N of force, I'd say they'd probably be able to generate zero energy.

Work (energy) is force times distance. Power is force times distance divided by time. That and mechanical advantage (divide or multiply by the ratio of the lever arms or gear ratios) are the only concepts you need here.
 
  • #3
Thank you very much for your answer.
So let's take this for example:

I pull a box which weighs 10 Kg, attached to a pulley.
The pulley is at a height of 10 meters. And i pull the rope for 10 meters, so the box will be at a height of 10 meters. Then, let's assume that i do this process in a total of 1 hour. Then will that be right:

(10 Kg * 10 meters)/3600 seconds = 100/3600

Is that right so far? If yes, what will 100/3600 equal to? Newtons? How can i convert my answer to kWh? May you please give me an example of how you would have solved this? Thanks.
 
  • #4
A kg is 9.8 N, so it is 10*9.8/3600=0.027 Joules/second (watts)

Kwh and watt-hours are energy, watts is power. .027 watts for 1 hour is .027 watt-hours or .000027 kWh.
 
  • #5
An easier way to estimate this would be as follows:
A 155lb person on a stationary bicycle burns about http://www.nutristrategy.com/activitylist.htm" . If you optimistically assume a 50% efficiency in the human converting food energy to mechanical energy and 50% efficiency converting the mechanical energy into electrical energy then you are generating 88 kcal/hr of electricity which is 102 watts.
 
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1. What is mechanical energy?

Mechanical energy is the energy possessed by an object due to its motion or position. It can be classified into two types: kinetic energy, which is the energy an object has due to its motion, and potential energy, which is the energy an object has due to its position or shape.

2. How is mechanical energy converted into electricity?

Mechanical energy can be converted into electricity through the use of generators. Generators use a mechanical energy source, such as wind, water, or steam, to rotate a coil of wire in a magnetic field. This motion induces an electric current in the wire, producing electricity.

3. What is the difference between mechanical energy and electrical energy?

Mechanical energy is the energy associated with the motion or position of an object, while electrical energy is the energy associated with the movement of electrons. Mechanical energy can be converted into electrical energy, but they are two distinct forms of energy.

4. How does mechanical energy impact our daily lives?

Mechanical energy plays a significant role in our daily lives. It powers our cars, trains, and airplanes, allowing us to travel long distances. It also powers machines that we use in our homes and workplaces, such as refrigerators, washing machines, and elevators. Additionally, mechanical energy is harnessed for renewable energy sources like wind and hydropower.

5. How do we measure mechanical energy?

Mechanical energy is typically measured in joules (J) or foot-pounds (ft-lb). The amount of mechanical energy an object has is dependent on its mass, velocity, and position. Kinetic energy is calculated using the formula KE = 1/2 * m * v^2, where m is the mass of the object and v is its velocity. Potential energy is calculated using the formula PE = m * g * h, where m is the mass of the object, g is the acceleration due to gravity, and h is the height of the object.

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