Can someone check my answers ? if i'm wrong explain .

9.

The angle is larger than 60o. You must add 180 to the 60 because the 60 is in the third quadrant. I do understand why you did that however. It's one more wrinkle in the question.  

theta = 240

x = 6 * cos(240) Remember that the cos always describes x if the angle is made with the x axis.

x = - 3

y = 6 sin(240)

y = -5.19

In the third quad, x and y must both be minus.

10

So far vectors are always broken down in terms of the x axis. In other words theta must start on the x axis (and usually) theta moves counter clockwise. If it moves clockwise, it is - theta as in other questions you've had.

In this case theta = 90 - 37 = 53. that makes it in reference to the x axis

Ax = 12 * cos(53) You will Never Never get a component larger than the vector producing it. Never going to happen.

Ax = 7.22

Ay = 12*Sin(53)  

Ay = 9.58

thermal energy is the answer