# B Help on Circular motion

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1. Nov 27, 2017

### Oliver Gough

<Moderator's note: Removed template prior to moving it from Homework.>

I am looking at centripetal acceleration, and I know that even at a constant speed the object is acceleration because its velocity is changing. But I don't understand how it is changing, like when is it negative and when is it positive ? Like if you were to make a simulation of the object going round in circles what would the velocity look like as it goes around, negative when down and positive when up? What about horizontal?

Last edited by a moderator: Nov 27, 2017
2. Nov 27, 2017

### Staff: Mentor

How do you describe velocity?

3. Nov 27, 2017

### Oliver Gough

Speed with a direction. I know it's direction is changing but how does it PHYSICALLY change? If you were to actually write down the velocity at each moment.

4. Nov 27, 2017

### Staff: Mentor

5. Nov 27, 2017

### Oliver Gough

No?

6. Nov 27, 2017

### jbriggs444

Velocity is a vector. One easy way to write it down is as an ordered pair (x,y) using cartesian coordinates.

7. Nov 27, 2017

### Drakkith

Staff Emeritus
Are you looking for a derivation of the math describing circular motion (including the change in velocity)?

8. Nov 27, 2017