# How does an object start to move in a circlular path?

1. Jun 19, 2013

### safwan.hossain

So, if an object is moving in a circular path, it has a force constantly directed to the center acting on it, and this force is perpendicular to the velocity. However, imagine now that it's not moving. How can one get this object to move in a circular pathway using centripetal force? Does the object need to have some initial velocity that the centripetal force needs to act on? Basically, how can one cause an object at rest to move about in a circular path?

Thanks
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jun 19, 2013

### voko

There are infinitely many ways to do that, but the important thing is that the object must be given the right velocity at the right distance from the center.

3. Jun 19, 2013

### rcgldr

To produce any change in speed, there needs to be a component of force (acceleration) in the direction of the path of the object (which would not be a centripetal force or acceleration).

4. Jun 20, 2013

### Basic_Physics

It needs both a forward velocity and a sideways force to drive it around the (continuous) bend.

5. Jun 20, 2013

### CWatters

"Start to move" implies an acceleration. Requires a force with a component in the direction of motion. Does centripetal force/acceleration have such a component? No, it's at right angles to motion. If it did then objects moving in a circle would get faster and faster.

6. Jun 20, 2013

### PeterO

A simple example:

Sit in a car in a large, open, flat area.
Turn the steering wheel slightly off centre.
Start the engine.
Engage drive.
Release the brake and note what happens.

If that is all too slow, press slightly on the accelerator pedal.