# Homework Help: Swing Problem -

1. Oct 30, 2005

### ilovephysics123

Swing Problem --

Im looking at a swing problem with a swing at some angle theta from vertical. The swing is massless and a child with weight W sits at the end of the swing. How do i find the tension of the swing? Likewise, when the swing is vertical?

Thanks!

2. Oct 30, 2005

### Päällikkö

You should divide the forces into x and y components. What do you think would be the best directions for x and y?

3. Oct 30, 2005

### ilovephysics123

I tried, but i got something like the x component of tension being the Force Applied/sin theta and the y component being the weight over sine theta or something like that, but i need to find it in terms of weight and theta.

4. Oct 31, 2005

### Päällikkö

Try with y being into the rope's direction.
What then should forces in that direction equal?

5. Oct 31, 2005

### PhysicsinCalifornia

Ok, think about this: When the child sits on the swing at rest, what are the forces acting on the child on the swing? At least one contact(tension)force and one non-contact(weight) force. (Is there normal force, if not, then tension force and weight force are equal and opposite right?)

Now the child is in motion. On standard x-y axis, the weight is straight down and tension is $$\theta$$ from the vertical. Now use your vast knowledge of trigonometry(or even geometry) to find where that angle goes, and set the sum of the forces in the x-direction and y-direction