Physics Problem***?

Question

How do you do this problem? Could you please help me out?

http://img84.imageshack.us/img84/411/61849804vo8.jpg

Answer 1

The normal force perpendicular to the surface of the incline is
N=5*9.8*cos(30)+5*a*sin(30)
the frictional force holding the block from sliding up the incline is
N*0.5
this force is balanced by
5*a*cos(30)-5*9.8*sin(30)

therefore

(5*9.8*cos(30)+5*a*sin(30))*0.5=
5*a*cos(30)-5*9.8*sin(30)

a) solve for a

a=9.8*(cos(30)*0.5+sin(30))/
(cos(30)-sin(30)*0.5)

a=14.84 m/s^2

b)
N=5*9.8*cos(30)+5*a*sin(30)
N=79.5 N

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