# Uniform circular motion particle problem

## Homework Statement

At t1 = 3.00 s, the acceleration of a particle moving at constant speed in counterclockwise circular motion is

a1=(6m/s2)i+(5m/s2)j

At t2 = 4.00 s (less than one period later), the acceleration is

a2=(5m/s2)i-(6m/s2)j

The period is more than 1.00 s. What is the radius of the circle?

T= (2∏r)/v
a=v2/r

## The Attempt at a Solution

I drew out the vectors, but that's all I could do with the problem. Maybe I'm supposed to integrate to find velocity or something? I just really don't understand where to start. If I knew that, I could probably finish it up. But there's so much information given in the book for circular motion, I don't know what to do with it.

ehild
Homework Helper
What angle the acceleration vectors do enclose? What can be the total time period? What is the magnitude of the acceleration? How is the acceleration related to the angular speed and radius of circle?

ehild

I don't know whether I'm supposed to find the angles of the individual vectors or average the acceleration over the given time period then find that one angle. And once that's done, I don't know what do with that information either. I wish I had a better professor, all he does is prove equations during class. Never goes over any examples.

ehild
Homework Helper
Try to answer my questions. That will lead to the solution. It is uniform circular motion. The acceleration is centripetal. The acceleration vectors are along the radii. What is the angular displacement of the particle from t1 to t2?

ehild

#### Attachments

• angular displacement.JPG
6.7 KB · Views: 552