Angles of a Vector on the Coordinate Plane

AI Thread Summary
The discussion revolves around identifying angles equivalent to 18 degrees below the -x-axis in a physics homework problem. The user initially selected option A but later expressed confusion about their choices and sought clarification on the correct answers. They considered changing their selections based on their reasoning but were unsure. Ultimately, the user realized their mistake and felt relieved after figuring it out. The conversation highlights the importance of visualizing angles on a coordinate plane for better understanding.
dwagz
Messages
3
Reaction score
0

Homework Statement



This question is on my physics homework, I guess it could be posted elsewhere, but I'm not sure where. Here is the problem:

Which of the following are the same as 18 degrees below the -x-axis? Choose all that apply:

!The choices I selected are in red!

A) 72 degrees left of the -y-axis
B) 72 degrees right of the +y-axis
C) 18 degrees right of the +y-axis
D) 72 degrees below the -x-axis
E) 18 degrees above the +x-axis
F) 72 degrees above the +x-axis
G) 18 degrees left of the -y-axis

Homework Equations


None

The Attempt at a Solution


I got the answer wrong. I chose choice A. because I subtracted 90 degrees (-y-axis) from 18 giving me 72.

I am thinking that I should change choice B. to C.and choice E. to F.? However, honestly I'm confused with my reasoning behind this. Nothing in my text speaks on this. Can anyone help? Thanks for your time.

Also, if my question would be best answered in another place, please let me know. Like I said, this is from my physics homework...
 
Physics news on Phys.org
This seems quite simple.

Try Drawing a graph to illustrate what it may look like.

Then try to see which fits the descriptions best.

I think http://www.studentforums.biz/index.php site, will be able to give you a quicker reply, as they specialize in homework
 
Last edited by a moderator:
Oooops I figured it out and I feel really silly lol.

Thanks for the reply anways!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top