What Is the Coefficient of Kinetic Friction Between the Ramp and the Crate?

AI Thread Summary
The discussion revolves around calculating the coefficient of kinetic friction between a crate and a ramp, given specific parameters like the mass of the crate and the angle of incline. A participant initially calculated the coefficient to be 1.22 but expressed doubt about the relevance of the masses in the calculation. Others pointed out that the provided coefficient would not allow the crate to slide down the ramp, indicating a potential error in calculations. The importance of showing work for clarity and verifying calculations for plausibility was emphasized. Ultimately, participants acknowledged mistakes in trigonometric functions used in their calculations, leading to a reevaluation of the problem.
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A steel washer is suspended inside an empty crate from a light string attached to the top of the crate. The crate slides down a long ramp that is inclined at an angle of 37 above the horizontal. The crate has mass 154 kg. You are sitting inside the crate; your mass is 61 kg. As the crate is sliding down the ramp, you find the washer is at rest with respect to the crate when the string makes an angle of 56 with the top of the crate. What is the coefficient of kinetic friction between the ramp and the crate?

I got roughtly 1.22 but my answer did not involve the masses so I am a little sus.
 
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With that coefficient of friction the crate would not slide down the ramp.

It is impossible to tell what went wrong if you don't show your work (that's what the homework template was for, but you can also edit it into your post now).

Do you expect the masses to matter?
 
mfb said:
With that coefficient of friction the crate would not slide down the ramp.

It is impossible to tell what went wrong if you don't show your work (that's what the homework template was for, but you can also edit it into your post now).

Do you expect the masses to matter?

My work was very sloppy and would not really make sense, and yes it would slide down the ramp, check your calculations. I also would not think that the masses would matter, but they were given in the problem and I am not a master of physics, so I am not sure.
 
physicsquestionboi said:
yes it would slide down the ramp, check your calculations.
Check yours. E.g. with a coefficient of 1 it would require an angle greater than 45 degrees to slide down.
 
haruspex said:
Check yours. E.g. with a coefficient of 1 it would require an angle greater than 45 degrees to slide down.

right nvm i have cos37 and sin37 backwards thanks fool
 
physicsquestionboi said:
right nvm i have cos37 and sin37 backwards thanks
So what answer do you get now?
 
Not everything that is given must be relevant. Finding out what is relevant and what is not is rarely practiced in homework problems, unfortunately.
physicsquestionboi said:
and yes it would slide down the ramp, check your calculations.
I didn't need a calculation to see that it would not, using the same argument as haruspex.
Checking answers for plausibility is often useful.
 
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