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a) Find acceleration of the block.

b) Find the coefficient of kinetic friction between the blcok and the incline.

For a) x = vot + 1/2at^2 --> a = 1.778m/s^2

For b) *here's where i'm having some problems*

I tried doing it two different ways and i get two different answers.

Way 1:

Ff = uFn

Ff/Fn = u

mgsinx/mgcosx=u

tanx=u

u = .577

Way 2:

ΣF=ma

mgsinx - umgcosx = ma

gsinx - ugcosx =a

a-gsinx/-gcosx = u

(1.778m/s^2 - 5m/s^2)/-(10*cos30) = u

u = .372

which way is wrong?