# Uniform Circular Motion

1. Sep 6, 2009

### White_Light

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

A particle of mass m=1kg moves counterclockwise in a horizontal circle of radius r=1m with uniform speed of 1 m/s. Determine the velocity, acceleration, total force and the component of the the total force on the particle in direction of its velocity as a function of the angle.

2. Relevant equations

a = v*v / r
F=ma

3. The attempt at a solution

Velocity = - 1 m/s
(negative sign is to indicate the direction of the particle moving counterclockwise)

Acceleration, a = 1

Total force,F = 1N

Is there anyone can help me to confirm my answer? Especially the velocity....

2. Sep 6, 2009

### Staff: Mentor

Velocity, acceleration, and force are all vectors. You must specify their direction as a function of angle. (I would use unit vectors and some trig functions.)

3. Sep 6, 2009

### Redbelly98

Staff Emeritus
I'm not familiar with using negative values to express the counterclockwise direction, is that a convention your professor said to use? It may be that just saying "1 m/s, counterclockwise" could be sufficient.

Your values for a and F are correct, but you are probably expected to indicate their direction as well.

EDIT: ahh, Doc Al responded faster than I.

4. Sep 6, 2009

### White_Light

Thanks for the comments! I will try again ^.^

5. Sep 6, 2009

### semc

Shouldn't you express the velocity in terms of rad/s since the last part say express as a function of the angle? If that is the case then acceleration would have to change too?

6. Sep 6, 2009

### Staff: Mentor

They are asking about linear velocity (the tangential velocity) not angular velocity.