What is the minimum work needed to push a car

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Homework Help Overview

The discussion revolves around calculating the minimum work required to push a car up an incline, specifically a 1025 kg car over a distance of 200 m at a 17.5° angle. The problem presents two scenarios: one without friction and another with a specified coefficient of friction.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the concept of work and its effects on the energy of the car. Questions arise about the necessity of understanding work in this context and how to calculate it. There is also a suggestion to apply the work-energy theorem to analyze the problem.

Discussion Status

The discussion is active, with participants questioning the role of work in the problem and discussing the implications of friction. Some guidance has been offered regarding the work-energy theorem, but there is no explicit consensus on the approach to take, particularly for the scenario involving friction.

Contextual Notes

Participants are considering the effects of friction and the assumptions made in the calculations, particularly in the second part of the problem. There is an emphasis on understanding the underlying principles rather than simply calculating a numerical answer.

bosox3790
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What is the minimum work needed to push a 1025 kg car 200 m up along a 17.5° incline?

(a) Ignore friction.
I got 604117.9512J
(b) Assume the effective coefficient of friction retarding the car is 0.40?
how do I get this one?
 
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for a) what does work do? What aspect of the car does it change? How do you calculate the work done then?
 
Do I need to know Work in this case?
 
bosox3790 said:
Do I need to know Work in this case?
you can calculate work

work changes the energy
 
Use the work-energy theorem:
[tex]W= \Delta K + \Delta U + |W_{fric}|[/tex]
To find the minimum work, push the block slowly so that [tex]\Delta K=0[/tex]. In (a), W_fric = 0. What is W_fric in (b)?
 

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