A 3.00-kg block starts from rest at the top of a 35.5° incline and slides 2.00m down the incline in 1.60 s.

(a) Find the acceleration of the block.

(b) Find the coefficient of kinetic friction between the block and the incline

(c) Find the frictional force acting on the block.(N)

(d) Find the speed of the block after it has slid 2.00 m.

I found A to be correct at 1.5625 m/s2
I found D to be correct at 2.499 m/s

I need help with B and C PLEASE!

(Forces)

I agree with your answer for a.

newton's second law applied to the box states:

sum of forces = m a

calling down the plane the positive direction:

mg sin(theta) - u m g cos(theta) = ma where u is the coefficient of friction

or: g( sin(theta) - u cos(theta) = 1.56m/s/s

g=9.8m/s/s, solve for u: 0.52

therefore frictional force = u N = u mg cos(theta) = 12.4N