# Circular Motion Edexcel A level Doubt

1. Jan 22, 2012

### thegoldengirl

Circular Motion Edexcel A level Doubt !!

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

In Formula One racing, cars often take corners at speeds in excess of 50 m s-1, and
so there is a very real danger of skidding.
(a)At a corner of radius 260m the track is banked at 20°. Calculate the maximum speed if no frictional force is required.

(b)'Downforce' is used to keep a car in contact with the track. The motion through the air produces a force perpendicular to the direction of travel, pushing the car onto the track. A racing car of mass 720 kg takes an unbanked corner of radius 550 m at a speed of 50 m s-1. The maximum frictional force is 0.4 x (reaction from track).Calculate the downforce necessary to prevent the car from skidding outwards.

2. Relevant equations

I know we have to use the Fc = mv^2 / r but not sure how ?! =/

3. The attempt at a solution

I have a Math exam tomorrow so I'm studying Math and it's not my doubt it's a doubt of one of my colleagues so You'd be doing him a BIG TIME favor if you help solving this :)

2. Jan 22, 2012

### Clever-Name

Re: Circular Motion Edexcel A level Doubt !!

Draw a picture as if you're looking behind the car on the slope. Think about the forces involved. You're right that you have to use Fc = mv^2 / r but what direction is that force acting on the car? What direction is gravity acting on the car?

We can't just solve the problem for you, but we can give you hints to find the answer yourself.

3. Jan 22, 2012

### technician

Re: Circular Motion Edexcel A level Doubt !!

For part(a) you need to draw a diagram as Clever-Name has suggested.
A little tip......Since there is no friction there are only 2 forces of any consequence acting onthe car...The force of the banked track on the car and the force of gravity (the weight of the car)

4. Jun 3, 2013

### norden

how to draw the diagram ?

5. Jun 4, 2013

### SteamKing

Staff Emeritus
The track is banked at 20 degrees. What does that look like? Draw a car on the bank. Label the forces acting on the car.