Physics .. 2 questions !

Not necessarily, the question mentions that the weight is supported by the two wires which indicates it's at rest.

The first problem can be solved with trigonomy.

To sustain the weight each cord will need to deliver a power of 50N on the y-axis.

You can represent the forces in a triangle like this, in which |AC| is the power delivered by tension in the cord:

|BC|=50 N so |AC|=|BC|/cos(50)=50/cos(50)=77.79. This means each cord delivers a power of 77.79N due to tension. Which would mean that the correct answer is D.

The second problem can be solved with the formula:

$${\frac{\left({Y}{\left({\mathtt{A}}\right)}{\mathtt{\,-\,}}{Y}{\left({\mathtt{B}}\right)}\right)}{\left({X}{\left({\mathtt{A}}\right)}{\mathtt{\,-\,}}{X}{\left({\mathtt{B}}\right)}\right)}} = {\mathtt{slope}}$$

We take the points A (-4,0) and B (0,-6) and insert them in the formula:

$${\frac{\left({\mathtt{0}}{\mathtt{\,\small\textbf+\,}}{\mathtt{6}}\right)}{\left({\mathtt{\,-\,}}{\mathtt{4}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0}}\right)}} = {\mathtt{\,-\,}}{\frac{{\mathtt{3}}}{{\mathtt{2}}}} = -{\mathtt{1.5}}$$

The correct answer is A.

for question 20 ... 

I think that they should say in the question that the weight is in Equilibrium   right ~ !