Centripetal Acceleration of car

[bgrove]

Homework Statement

Two cars drive around in circles at constant speeds. Car B's circle is twice as large as car A's, but its centripetal acceleration is three times as large. How many times faster is car B driving than car A?

Homework Equations

I'm trying to use a=(v^2/r) for centripetal acceleration.

The Attempt at a Solution

I don't really know where to start on this one.

Per our answer key, the answer should be: 2.45 times faster.

 

[Phys student]

You want to find a relation between the velocity of car A and car B, and you're given a relation between the radii of their circular paths and a relation between their centripetal accelerations. Try to write down some equations.

 

[Chestermiller]

Use subscripts to represent the parameters for A and B. Thus, r_A, v_A, and a_A are the radius, velocity, and acceleration of A, respectively, and similarly for B. Now, in terms of these parameters, write the centripetal acceleration equations for A and B respectively. How is r_A related to r_B? How is a_A related to a_B? This should give you enough to solve the problem.

Chet