What Are the Gravitational and Normal Forces on a Skier on a Slope?

AI Thread Summary
The discussion revolves around calculating the gravitational and normal forces acting on a skier descending a slope. The gravitational force exerted by the skier is calculated as 528.5 N using the formula involving mass and gravitational acceleration. The normal force, which is the reaction force exerted by the slope on the skier, is determined by analyzing the free-body diagram and recognizing that it equals the vertical component of the skier's weight. There is confusion regarding the terminology of "gravitational force exerted by the skier on the slope," with some participants suggesting it may refer to the vertical component of the contact force. Clarification on these terms is necessary to ensure accurate understanding and calculations.
j doe
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Homework Statement


A 60 kg skier is beginning her descent down a 26 degree slope. The frictional force between the skis and the snow is 4 N
a) What is the gravitational force the skier exerts on the slope?
b) What is the normal force the slope exerts back on the skier?

Homework Equations

The Attempt at a Solution


a) What is the gravitational force the skier exerts on the slope?
60(kg)*9.8(m/s^2)*cos(26) = 528.5(N)

b) What is the normal force the slope exerts back on the skier?
not sure how to do this one
 
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First, sketch a free-body diagram. Use the slope as the X axis. Since there is no acceleration in the Y axis of this system, you can solve for the normal force.
 
did i do part a correctly?
 
As there is no acceleration in the Y axis, it means the force exerted by the skier on the slope and the one the slope exerts on the skier is the same. It's kind of the definition of the normal force, it is a force exerted by the surface on the object, it is a force of reaction to another one, which here is the gravitational force.
 
j doe said:
a) What is the gravitational force the skier exerts on the slope?
Is that the word-for-word statement of the question? It doesn't make any sense.
The Earth exerts a gravitational force on the skier, and the skier exerts an equal and opposite gravitational force on the Earth; the skier exerts a contact force on the slope, which can be resolved into a combination of forces in different directions, like normal and tangential.
I do not know what "the gravitational force exerted by the skier on the slope" means. Maybe it means the vertical component of the contact force?
 
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