# Plot motion of particle with constant speed and angular velocity

1. Sep 27, 2012

### S_Flaherty

Consider the problem of a particle sliding inwards with a constant speed c and starting at radius R=pc/Ω, on a platform rotating with a constant angular velocity Ω. Give a plot of the trajectory of the particle from r=R to r=0, for p=0.5, 1, 2, 6.

I'm a little confused on how to do this. If there is no acceleration, then would the plot just be a series of straight lines? And should I plot r vs t even though time isn't mentioned at all?

2. Sep 27, 2012

### voko

"Sliding" would imply that there is no friction with the platform, in which case the trajectory should indeed be a straight line - in an inertial frame of reference. Are you perhaps supposed to find the trajectory in the platform's frame?

3. Sep 27, 2012

### S_Flaherty

Also, how can something slide inward if it's moving in circular motion? Wouldn't centripetal force cause it to slide outward?

4. Sep 27, 2012

### voko

That's why I think there is no friction.