# Homework Help: Spring at an angle?

1. Mar 30, 2012

### rasputin66

A 8.5 kg board is wedged into a corner and held by a spring at a 50.0° angle, as the drawing shows. The spring has a spring constant of 184 N/m and is parallel to the floor. Find the amount by which the spring is stretched from its unstrained length.

(The picture shows a spring sticking out of the wall horizontally, and it is attached to one end of the board. The spring is holding the board up from falling flat on the floor. So the board is pulling on the spring.)

I know how to do some spring questions, but I don't know how to plug in the angle in this question. Please help! I know I need to find N to find x.

00000 <~~ spring
| / <~~~ board
| /
|/

m= 8.5 kg
angle= 50 degrees
k= 184 N/m

2. Mar 30, 2012

### Staff: Mentor

What forces act on the board? What are the conditions for equilibrium?

3. Mar 30, 2012

### rasputin66

Gravity? And the spring?

They equal zero? I think I'm missing something. Like how to figure in this angular business.

x = (mg/k)
x=(9.8x8.5)/184
x=0.565 m<~~~ not right

Last edited: Mar 30, 2012
4. Mar 30, 2012

### Staff: Mentor

Yes, those are the two most important forces.
What is the condition for rotational equilibrium?

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