Calculate Electric Power from Mass, Radius & Velocity: 3000 Joules to Watts

[Hanababa]

A mass M is at the top of a rotative arm, with a radius R, at a certain speed V.
Lets take M=60kg, R=5meters and V=10m/s.
We assume the movement generated from some kind of natural source (wind, water..), is permanent and constant, and there is no loss (100% efficiency).
How many watt of electrical power this device can produce ?

I find 3000 Joule of energy generated, but I need an answer in watt, not in Joule. As 1J = 1watt*second, I do not see how to convert it.
The formula I used is
Etot in Joule = 1/2 * M * R² * (V/R)²

What have I missed ?

 

[AC130Nav]

One of my books has 1 watt = 1 Joule/second not Joules * seconds. Watts are power; have you looked for that formula?

 

[Hanababa]

Exactly, 1 J = 1watt.second
This is the reason I am confused.
As we speak about an electric power generator, we need a result in watt , not in watt.second
Can someone clarify ..?

Truly Appreciate it

 

[Paulie323]

Don't quote me on this but I don't think you can convert from joules to watts. this is due to the fact of what AC130Nav said 1 watt is the equivalent of 1 J/s. So the only way to have your answer in watts is if your original before converting is in Joules/second not just Joules, this would be the only way to convert to watts.

Hope I helped in clarifying things! :)

 

[Hanababa]

Thanks for your clarifications.

I however would like to understand what is wrong.
1. Is it a mistake to think that the device described is able to generate electrical power ? After all, it is very similar to a wind turbine system.
2. Is it a mistake to think that the characteristic of an electric power generator is in watt (only), not in watt.second or watt/second ?
3. If answers to both previous questions are negative, is it that some data are missing from the description ?
In other words, how much power would this device be able to provide, this is all I really would like to know. Once again, it rotates thanks to a permanent and constant natural input.

 

[OmCheeto]

Is this a homework problem, or something you made up?

 

[Hanababa]

I am away from school since a long time. The value I put for M,R and V are fictive, I just would like to know how to calculate it.

 

[OmCheeto]

I am away from school since a long time. The value I put for M,R and V are fictive, I just would like to know how to calculate it.

That's what I suspected. Your problem as stated, has no solution.

A mass M is at the top of a rotative arm, with a radius R, at a certain speed V.
Lets take M=60kg, R=5meters and V=10m/s.
We assume the movement generated from some kind of natural source (wind, water..), is permanent and constant, and there is no loss (100% efficiency).
How many watt of electrical power this device can produce ?

I find 3000 Joule of energy generated, but I need an answer in watt, not in Joule. As 1J = 1watt*second, I do not see how to convert it.
The formula I used is
Etot in Joule = 1/2 * M * R² * (V/R)²

What have I missed ?

 

[Hanababa]

What other parameter(s) do we need to mention in order to get a solution ?

 

[OmCheeto]

What other parameter(s) do we need to mention in order to get a solution ?

The initial parameters can be stated an infinite number of ways.
You simply need to know the energy per unit time that is being added to and extracted from your device.

 

[Hanababa]

...Does not help me much, am really confused, but thanks anyways