Power Needed to Pull Skier Up Slope

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In summary, the problem involves a skier being pulled up a slope by a motor-driven cable. The mass of the skier is 78.7 kg and the speed is constant at 1.04 m/s. The coefficient of kinetic friction between the skis and the slope is 0.270. The power that must be delivered by the motor pulling the cable can be found using the equation P=FV, where F is the net force on the skier. To find the net force, the normal force and force of friction must be considered. The force of friction can be calculated using the equation umg, where u is the coefficient of kinetic friction and mg is the normal force. The normal force can be determined by balancing
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Jm4872
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Homework Statement


A skier of mass 78.7 kg is pulled by a motor-driven cable up a 31.9 ° slope at a constant speed of 1.04 m/s. If the coefficient of kinetic friction between the skis and the slope is 0.270, what power must be delivered by the motor pulling the cable?

Homework Equations



P=FV

The Attempt at a Solution


The Fnet of the skier will be 0 because the velocity is constant.
To find the F|| of the skier I used the equation mgsin(x) and umg to find Force friction(Ff)
Therefore, T=F||-Ff
and therefore P=T*v
but everytime I do this I get the wrong answer, and I don't know why??Please help!
 
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  • #2
To find the force of friction, you need the normal force, which is balancing w_perpendicular (mg cos x). Force of friction is mu times this normal force.

And also, are w_parallel and friction in the same direction as each other, or opposite? Is just one of these forces or both of them pointing opposite of tension?
 

1. How is the power needed to pull a skier up a slope calculated?

The power needed to pull a skier up a slope is calculated by multiplying the force required to move the skier uphill by the velocity at which the skier is being pulled.

2. What factors affect the power needed to pull a skier up a slope?

The factors that affect the power needed to pull a skier up a slope include the weight of the skier, the angle of the slope, the coefficient of friction between the skis and the snow, and the speed at which the skier is being pulled.

3. How does the angle of the slope affect the power needed to pull a skier up?

The steeper the slope, the more power is needed to pull a skier up. This is because the force required to move the skier uphill increases as the angle of the slope increases.

4. Is the power needed to pull a skier up a slope constant?

No, the power needed to pull a skier up a slope is not constant. It varies depending on the factors mentioned above, such as the weight of the skier and the angle of the slope.

5. How can the power needed to pull a skier up a slope be reduced?

The power needed to pull a skier up a slope can be reduced by reducing the weight of the skier, choosing a shallower slope, and minimizing friction between the skis and the snow.

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