Kinetic Friction and Incline for a Car

AI Thread Summary
The discussion focuses on the dynamics of a car accelerating up an incline, analyzing the forces acting on it. The key equations involve friction, normal force, and the components of gravitational force on the incline. The confusion arises regarding the direction of friction; while it typically opposes motion, in this scenario, it actually aids the car's acceleration up the incline. The participant realizes that the friction force acts in the positive x-direction, aligning with the car's movement. This insight clarifies the relationship between friction and acceleration in the context of inclined motion.
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Homework Statement


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Homework Equations


friction:[/B] f = μN
incline angle: θ = arctan(1/10)
summation of forces in y: N - mgcosθ = 0
summation of forces in x: -f - mgsinθ = ma (?)

The Attempt at a Solution


For this problem, I set the x-axis going up the incline and the y-axis normal to said x-axis. When I drew the FBD, the part that did not make sense to me was the summation of forces in the x-axis. The question wants the car to accelerate UP the incline, but the two forces I draw for the FBD both point down the incline. One of the forces is the x-component of the weight, mgsinθ, and the other is the friction. I know the weight's x-component direction is right, so the wildcard is the friction. Isn't friction opposite to the direction of motion?
 
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I just had a thought... is friction the force which drives the car forward? The wheels spin in the negative x-direction (with respect to the ground) so the friction points to the positive x-direction. If that were the case it would make a lot of sense!
 
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