How do you solve this Mechanics/friction question?

Question

Kinda stuck, so I'd appreciate the steps.

Answer 1

You must consider the components of the weight:

1. Normal component to the desk:

$$W_{\perp}=W\cos\alpha$$

2. Parallel component to the desk:

$$W_{||}=W\sin\alpha$$

where $\alpha$ is the given angle.

So the frictional force is: $$F=0,6\cdot W_\perp=0,6\cdot 8N\cos28$$

Now you can also evaluate $W_{||}$ and see if $W_{||}\ge F$.

Answer 2

Hint:

Here is how the forces will go. You have to make de decomposition of the weight $\overrightarrow{P}$ on the axis $x$ and $y$ in order to find the equilibrium.

In the $x$ direction you will have the friction force $\overrightarrow{Fr}$ and the part $\overrightarrow{P}\cdot \sin 28º$.

In the $y$ direction you will have the normal force $\overrightarrow{N}$ and the part $\overrightarrow{P}\cdot \cos 28º$.

Can you finish?