How do you find the coefficient of friction of an object sliding down an inclined plane.

Given:
m = 10 kg
length of plane = 5.0 m
Height of plane = 2.5 m

2 answers

If it is sliding at constant velocity, then mu = tangent angle= height/base

where base=sqrt(length^2-height^2)
A yo-yo has a string length of 0.200 m.
Its mass = 1.5 kg

What is the slowest speed at which you can spin it to keep it in a fixed path?

Help Please?