Eraser sliding down slope - Friction

AI Thread Summary
To find the coefficient of friction for an eraser sliding down a slope, start by identifying the forces at play: gravity, friction, and the normal force. The problem involves a slope with a height of 1m and an angle of 35 degrees, taking 1.8 seconds for the eraser to slide down. Since the forces are constant, you can apply uniform acceleration equations to calculate the distance covered and determine the acceleration. By treating the mass of the eraser as 'm', the calculations can proceed without needing its specific value. The discussion concludes with the realization that understanding the forces and applying the right equations leads to a solution.
Kamataat
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An eraser slides down a slope of height 1m that makes an angle of 35 degrees with the ground. It takes the eraser 1,8s to do this. Find the coefficient of friction.

I have no clue how to do this. I've not been able to solve any of the equations I've tried, because there is always the mass of the eraser which I don't know.

- Kamataat
 
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Kamataat said:
An eraser slides down a slope of height 1m that makes an angle of 35 degrees with the ground. It takes the eraser 1,8s to do this. Find the coefficient of friction.

Start by identifying the forces in the problem. What are they? What is their magnitude? What about their direction?
 
Just call the eraser's mass 'm', it should take care of itself.
 
What am I supposed to do with the given time?

The forces are gravity, friction and the normal force?

- Kamataat
 
The forces are constant, and do not change throught time, so the acceleration will be constant, you can use the uniform acceleration equations with the time. Notice you can calulate the distance covered.
 
figured it out. thanks!

- Kamataat
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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