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# Coefficient of friction

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1. how do you find the COF without mass?
2. (Original post by Snowy_TM)
how do you find the COF without mass?
Example?
3. 10km/h
130m stopping distance
-25m/s deceleration
can you help me with the formula and explain how to do it for me please ?
4. (Original post by Snowy_TM)
10km/h
130m stopping distance
-25m/s deceleration
can you help me with the formula and explain how to do it for me please ?
F = frictional force
N = normal force

F = μN
normal force is the weight
F=μmg [1]

for a force accelerating a mass
F=ma [2]

combine [1] & [2]

ma=μmg

m cancels

a=μg

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PS your numbers look iffy, check how you got a deceleration of 25m/s^2
5. A=-u^2/2s
= 10^2/2*130
=0.384m/s
Can you put my results into an equation please to find the cof?

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