# Homework Help: Circular Motion Speed

1. Feb 8, 2012

### azncocoluver

1. The problem statement, all variables and given/known data
A 0.55 kg stone attached to a string is whirled in a horizontal circle of radius 19 cm as in the figure below. The string makes an angle of 35° with the vertical.

2. Relevant equations

3. The attempt at a solution

2. Feb 8, 2012

### tiny-tim

hi azncocoluver!

show us what you've tried, and where you're stuck, and then we'll know how to help!

(oh, and what actually is the question asking for? )

3. Feb 8, 2012

### azncocoluver

Haha wow, I totally forgot to put the question.
(a) Find the speed of the stone.
m/s

(b) Find the tension in the string.
N

I have no idea where to start. :[

4. Feb 8, 2012

### tiny-tim

hi azncocoluver!

nearly all dynamics questions boil down to good ol' Newton's second law (F = ma) …

so the first step is to draw a diagram with the forces and acceleration labelled,

and the second step is to write out the equation …​

what do you get?

5. Feb 8, 2012

Ft = Fg?

6. Feb 8, 2012

### tiny-tim

where's the acceleration (and the angles)?

7. Feb 8, 2012

### azncocoluver

No clue lol.. can you show me the solution because I've never done a problem like this before. I kind of learn better when I see an approach first :]

8. Feb 8, 2012

### Staff: Mentor

That's not the way it works here at Physics Forums.

In case you haven't seen the forum rules (https://www.physicsforums.com/showthread.php?t=414380), I have copied parts of them that are relevant to your post (emphasis added).