Centripetal force and acceleration problem

[ScienceGirl90]

Homework Statement

A 2500 kg car starts from rest and travels along a circular track with a radius of 55.0 meters. The car starts out at a position due East of the center of the track, heading due North initially around the track, which is counterclockwise. The car increases its speed by 105 m/s every minute around the track. How fast is the car traveling when it is 1/4 of the distance around the track? State the car's tangental velocity.

Homework Equations

v=2*pi*r/period

The Attempt at a Solution

I am unsure of how to begin this problem when I'm looking for only 1/4 of the distance. I'm also having a hard time finding the period of one full rotation around the track. Any help would be appreciated! Thanks.

 

[Delphi51]

In this case you are better off doing the magnitude and the direction separately. Figure out the distance for the quarter circle and translate the "105 m/s every minute" into an acceleration in m/s. Then treat it like a linear motion problem and just use your constant acceleration formulas to find the final speed.

 

[ScienceGirl90]

Ok, thank you. Would you mind explaining how I get 105 m/s every minute to m/s for acceleration?

 

[venkatg]

105m/s per minute translates to an acceleration a = of 105/60 = 1.75 m/sec/sec

To cover 1/4 th the circumference of a circle of radius is (1/4) * 2 * pi * r

this gives the distance "S"

Now use the formula velocity after covering S is =

V*V = 2* a * S