- #1

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## Homework Statement

List a couple factors that make efficiency less than 100%.

## Homework Equations

Efficiency = Eout / Ein

Eout = mgh

Ein = Work = FD

## The Attempt at a Solution

IDK :\

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- Thread starter iRamie
- Start date

- #1

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List a couple factors that make efficiency less than 100%.

Efficiency = Eout / Ein

Eout = mgh

Ein = Work = FD

IDK :\

- #2

- 525

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Essentially, I understand the question to be: what sort of things 'waste' energy in a system? What sort of things decrease the amount of useful energy you get?

- #3

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In that situation what makes it less than 100%

- #4

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## Homework Statement

List a couple factors that make efficiency less than 100%.

## Homework Equations

Efficiency = Eout / Ein

Eout = mgh

Ein = Work = FD

## The Attempt at a Solution

IDK :\

With this definition of efficiency it will be less than 1 if the object starts at some speed V0 and ends at some speed V1 with V0<V1.

This is because

[tex] W = \Delta K.E. + \Delta G.P.E. [/tex]

if the change in kinetic energy is positive, then

[tex] W > mgh [/tex]

and

[tex] \frac{mgh}{W} < 1 [/tex]

But i'm not sure that this definition for efficiency really makes sense.

- #5

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We have a lab in which there is a ramp with one end on the floor and the other end is on top of a few textbooks. Therefore, it has a slope, and an object is lifted using the ramp and the force is measured using a newton scale.

So in this case, what makes it less than 100%.

Assume the object is moving at constant velocity.

- #6

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- #7

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Is there anything else? Because it asks for 2 Major Factors.

- #8

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Is there anything else? Because it asks for 2 Major Factors.

Perhaps air resistance. What do you think?

- #9

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In the case of an inclined ramp, you're pushing/pulling, but not all that energy goes into moving the object. I think they just want you to list off possibilities for where that energy goes, though I'm pretty sure they want you to think about it, and not just copy down what someone tells you, which is why I'm not just giving you a list of things.

So, think about it. Why is it that it's harder to pull an object along carpet than it is to pull it on ice? Where does that energy go? That sort of energy loss is exactly why you can't get 100% efficiency. As far as what form this 'waste energy' takes, think about what happens when you rub your hands together really fast: what sort of energy is created? That sort of energy is one example of "waste" energy that keeps a machine from being 100% efficient.

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