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Power Question

by AZhang
Tags: force, kinetic, potential, power, work
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AZhang
#1
Nov20-10, 06:28 PM
P: 14
A 3400 KG truck is driving up a road inclined at 8 degrees above the horizontal. If the resistive forces such as air drag and friction that act on the car add up to 1200 N, determine the power output necessary to keep the velocity constant at 20 m/s.

I don't really get how to set up my equations. Can someone help me?
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Delphi51
#2
Nov20-10, 06:32 PM
HW Helper
P: 3,394
Have you got a formula for finding power? If not, try wikipedia.
AZhang
#3
Nov20-10, 09:02 PM
P: 14
I do, it's both Work/Time and Total Energy/Time, but I don't know how to use them in this scenario.

Delphi51
#4
Nov20-10, 11:16 PM
HW Helper
P: 3,394
Power Question

You need pick a convenient time OR distance to work with. Say you choose 1 second for the time. Then you must work out the distance along the incline that it goes in that time. And the height straight up that it goes. These numbers should allow you to calculate the energy used to overcome friction and the energy used to increase the height. Finally, P = energy/time should do the trick.


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