Using watts to help determine velocity?

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Homework Help Overview

The discussion revolves around determining the velocity of an abstract object using its mass, position, external forces, and power measured in watts. Participants explore the relationship between power, force, and velocity, questioning what additional information may be necessary to establish velocity from these parameters.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the possibility of calculating velocity from power and force, referencing the equation P=F*v. They also question whether force can be derived from power and how energy changes relate to kinetic energy and velocity.

Discussion Status

The conversation is ongoing, with some participants suggesting that knowing the object's initial conditions and the history of forces is crucial for determining its velocity. Others indicate that the starting point of the object being at rest simplifies the problem, provided the forces and durations are known.

Contextual Notes

One participant mentions that the simulation is set in a theoretical space without significant gravitational influence, which may affect the considerations for calculating velocity.

bluej774
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Here's what I know about an abstract object:
*mass
*position
*all external forces acting upon it (gravity ;)
*that it is exerting force upon itself
*direction of said force
*number of joules per second being used in said force (watts)

Can I use these to determine the velocity of the object? If not, what other information do I need? It's important that the joules per second (watts) be a part of the equation.
 
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as long as you can find a resultant force acting in one direction, you can calculate the velocity from the force and the power using P=F*v Power=Force*Velocity
 


Well, then, maybe this is a better question. Can you determine force from watts (joules per second) expended producing said force?
 
bluej774 said:
Here's what I know about an abstract object:
*mass
*position
*all external forces acting upon it (gravity ;)
*that it is exerting force upon itself
*direction of said force
*number of joules per second being used in said force (watts)

Can I use these to determine the velocity of the object? If not, what other information do I need? It's important that the joules per second (watts) be a part of the equation.

I think since velocity is the rate of change of position with respect to time, that without knowing some rate of change in position, as an initial condition, and the history of forces and energies affecting the object since, then you can't just tell from knowing all the forces acting on it at an arbitrary moment, because those forces result in accelerations, and those accelerations are only the rate of change of velocity at some point and don't necessarily speak to what it may be changing from or to.

I think you need to know it was at rest somewhere, or its velocity somewhere, and its history since to be able to determine what it's total kinetic energy (and hence velocity) is at the point of interest.
 


bluej774 said:
Well, then, maybe this is a better question. Can you determine force from watts (joules per second) expended producing said force?

J/s if you know the duration gives you joules and joules gives you energy added to the object and hence you know how much its kinetic energy may have changed.

But in reference to the prior post you only know how much it may have changed, and without knowing what it's kinetic energy is initially, then ...
 
I'm doing a simulation. That's why I need this info. I forgot to mention that the object begins at rest. However, the simulation is not in Earth's gravity. It is in a theoretical space without any major gravitational influence.
 
Well in that case yes.

You have position and it's at rest then all you need then is the forces and durations over its history to the moment of interest I'd say.
 
So, what is the equation to figure out force using joules per second?
 

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