# Homework Help: Motion and friction problem

1. Jun 12, 2007

### Sparky500

1. The problem statement, all variables and given/known data
Calculate the maximum speed a vehicle can travel round a horizontal bend of radius 50m without skidding if the coefficient of friction between tyres and road is 0.5.

2. Relevant equations
I am not sure about the equation. As radius and coeff of friction are given, maybe something along these lines? v = μr

3. The attempt at a solution
I am puzzled as there is no mention of the weight of the car. Would this not be required in order to work it out?

Thanks a lot.

2. Jun 12, 2007

### Staff: Mentor

Is the car accelerated? What forces act on the car? How would you apply Newton's 2nd law?

(Represent the unknown mass of the car by a symbol. "m" would be a good choice. Then work the problem out and see if you need the actual value or not.)

3. Jun 12, 2007

### Sparky500

I guess it will be gravity.

As to Newton F=ma (?).

Not sure whether it is accelerated, doesn't really say in question.

4. Jun 12, 2007

### Staff: Mentor

Gravity is not the only force acting on the car. (If it were, it would be falling!)

As far as whether it's accelerated, here's another clue:

5. Jun 12, 2007

### Sparky500

So there is also a velocity?