Question

A 15-kg box is resting on a wedge which has an angle of inclination of 30° and a coefficient of friction 0.15. What is the value of gravity's vector?

Answer 1

The component of the weight that points down the incline is 73.5 N.

Explanation:

Gravity's vector, `F_g`, is given by

`F_g = m*g = 15 kg*9.8 m/s^2 = 147 N` vertically down.

That is the weight of that box. You can resolve that force into a component perpendicular against the wedge's incline and one down the incline. I will assume you are asking for that second one.

The component of the weight that points down the incline, `W_"di"`, is

`W_"di" = m*g*sin30 = 147 N*sin30 = 73.5 N`

I can't think how to interpret your question to require use of the friction coefficient.

I hope this helps,
Steve