# The Banked Turn

1. Oct 15, 2006

### FortyFeet

Hey there. I took Physics B last year, but for some reason we never covered the banked turns when it comes to centripetal acceleration. So I need a bit of help on these two:

A curve with a 100 m radius on a level road is banked at the correct angle for a speed of 16 m/s. If an automobile rounds this curve at 30 m/s, what is the minimum coefficient of static friction needed between the tires and the road to prevent skidding?

and...

Aircraft experience a lift force (due to the air) that is perpendicular to the plane of the wings and to the direction of flight. A small airplane is flying at a constant speed of 250 km/h. At what angle from the horizontal must the wings of the airplane be tilted for the plane to execute a horizontal turn from east to north with a turning radius of 1900 m?

Thanks =D

2. Oct 16, 2006

### andrevdh

Welcome to PF FortyFeet. We will help you but you must show some attempts at the problems first.

Draw a little diagram with the two forces acting up on the car. "at the correct angle" means that the car will not tend to slip so it will not experience any frictional forces when going around the bend. This means only the normal force and weight are acting on the car.

Decompose the normal force into its x- and y-components.

Set the two force eqautions up in the x- and y-directions using Newton's second law. Post your two equations so that we can help you.

3. Oct 16, 2006

### gunblaze

haha.. Sounds quite funny calling it 'little'. It's supposed to be a free-body diagram ah?