Maximum power when torque is 0 and angular velocity is 0

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Homework Help Overview

The discussion revolves around a problem involving the calculation of power in a mechanical system, specifically focusing on the relationship between torque and angular velocity. The original poster presents a scenario where measurements of RPM and angular displacement have been converted into angular velocity and axial torque, leading to a linear equation representing torque as a function of angular velocity.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster questions the validity of calculating power when both torque and angular velocity are zero, expressing confusion over the implications of the power equation P = T*ω. Some participants suggest that when angular velocity approaches zero, torque may be high, indicating a constant power scenario. Others explore the implications of the linear relationship presented in the equation and its lack of maxima.

Discussion Status

The discussion is ongoing, with participants exploring the nuances of the problem and questioning the assumptions behind the calculations. Some guidance has been offered regarding the interpretation of the power equation, but no consensus has been reached regarding the implications of the linear equation or the nature of the problem itself.

Contextual Notes

The problem is framed within the constraints of a homework assignment, with limited information provided. Participants are navigating the challenge of interpreting the relationship between torque and angular velocity in the context of power calculations.

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Homework Statement



What is the power the drill can supply at the two points of interest(The intersections at the axis')

This is a direct translation of the dutch problem. So basically what's going on is we made measurements of the RPM and angular displacement of our mechanical system (irrelevant at this point) We then converted all the points (correctly) into angular velocity (the RPM points) and the angular displacement to axial torque applied. We then used a scatter plot to plot these points (as per instruction) and found an equation for the linear regression (all using MATLAB)

So it boils down to the fact that I have an equation like this:
y= 0.15781x + 155.11

Where y is axial torque as a function of angular velocity.

So to come back to my first point; they are asking for the power at the axis intersections so when there is no moment opposing the motor (maximum angular velocity) and when there is no angular velocity (so maximum moment -> drill stationary)

But how can this even be right? The equation for power is P = T*ω

So when either one is zero the answer is zero but this can't be right can it?

I hope I have explain it thoroughly enough...
 
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bamp?
 
P=T*w
when w is close to zero, T will be high since P is roughly constant.
 
Yes but the problem states we have to find the power at both T and w when they are close to 0. How should I got about doing this? This (first post) is all the information available
 
Ignore my earlier post; I wasn't paying attention.

y= 0.15781x + 155.11

When x=0, you can calculate the maximum torque. Since it's not turning, it's doing no work, and because power is rate of doing work, so power=0. :smile:
 
That's what I thought but it can't be THAT easy can it? But I guess it's some sort of a trick question because there are no maxima in a linear equation (which we were supposed to find) so 0 it is!
 

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