Friction force

1. The problem statement, all variables and given/known data



A 3 kg block is on a plane inclined at 30.0° with respect to horizontal.Coefficient of static friction C_sfbetween block and plane is 0.60.

What is normal force , and is the block moving ??



2. Relevant equations

Using second low of Newton (vectors):

F_g +f+N=ma.

So N=mg*Cos(30)

and we know that f=C_sf *N = mg cos(30)* C_sf

but considering the object not moving f= m*g*sin(30)

so the object must be moving

3. The attempt at a solution

IS IT CORRECT ?