A 10 kilogram block slides down a 30 degree inclined slope, the slope has a coefficient of friction of 0.2. Calculcate the blocks acceleration down the slope.

Resolving all forces in the vertical gives the normal force as 10gcos(30). Resolving all forces normal to the slope gives the frictional force as 2gcos(30) (given Friction = mu*R). Using second law, F=ma. 10gsin(30)-2gcos(30)=10a. a=3.2m/s.