Nonuniform circular motion of particle

[dumbdude]

a particle starting from rest revolves with uniformly increasing speed in a clockwise circle in the xy plane. The center of the circle is at the origin of an xy coordinate system. At t=0, the particle is at x=0.0, y=2.0 m. At t=2.0s the particle has made one-quarter revolution and is at x=2.0, y=0.0 m. Determine (a) its speed at t=2.0 s, (b) the average velocity vector, and (c) the average acceleration vector during this interval.



Where do I start

 

[Chi Meson]

You are doing angular kinematics here. From the information, you can determine the radius of the circle. You can also determine the initial angular speed, the angular displacement, and the time interval. Just like linear kinematics, if you know three of the variables, you can determine the other two (final velocity and acceleration, in this case).

I am assuming you are familiar with \theta \alpha and \omega?

 

[dumbdude]

thanks that's what i was thinking but wasnt sure

 

[Chi Meson]

also, remember that average velocity is defined as ∆s/∆t, and average acceleration is ∆v/∆t. You can see the answers if you draw vector diagrams of the initial and final conditions.