# 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_{sf}between 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 ?

http://ift.tt/1lue3KT

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