Mechanics

[Grover]

Here's a problem from my textbook. Hope somebody could give a hand.
The speed of a particle moving in a circle 2m in radius increases at the constant rate of 3m/s^2. At some instant, the magnitude of the total acceleration is 5m/s^2. At this instant, find the centripetal acceleration of the particle and its speed.

[Tom Mattson]

Hi, and welcome to PF.

You need to note that the total acceleration is given by:

a=(-v2/r)er+(dv/dt)eφ

where er and eφ are the unit vectors pointing in the radial and tangential directions, respectively.

edit: fixed subscript bracket