- #1
Yashbhatt
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Homework Statement
A block starts sliding on an inclined plane inclined at an angle θ with the horizontal. The first half of the plane is frictionless and the second half has a co-efficient of friction μ. When the block reaches the bottom of the slope, it has velocity zero. Calculate the co-efficient of friction.
Homework Equations
W = mg, N = mgcosθ, F = μN
The Attempt at a Solution
Actually, my friend has solved the problem and has got the correct answer but I don't know if his method is correct. He says, if we apply a force F to an object continuously(gravitational force in this case). Then, if we apply an equal and opposite force -F, then the body will acquire a constant velocity but if we apply twice that force, the body will come to rest. So, in this case,
2 μ mg cosθ = mg sinθ and μ = 2 tanθ which is the correct value for the co-efficient of friction. As the answer is correct, the method seems correct. But I don't know for sure. Is it correct?