# Centripetal Forces

1. Feb 22, 2009

### pats6

1. The problem statement, all variables and given/known data
As your plane circles an airport, it moves in a horizontal circle of radius 2100m with a speed of 400km/h. If the lift of the airplane's wings is perpendicular to the wings, at what angle should the plane be banked so that it doesn't tend to slip sideways

2. Relevant equations

3. The attempt at a solution

Last edited: Feb 22, 2009
2. Feb 22, 2009

### LowlyPion

So what are your thoughts on how to solve it?

3. Feb 22, 2009

### pats6

i do not know i tried to draw a diagram for the problem and when i worked the problem out i got a really small number

4. Feb 22, 2009

### pats6

i know that i need to find the horizontal lift components but im not sure how

5. Feb 22, 2009

### LowlyPion

If the plane is in equilibrium - flying in a circle - what do you know that must be balanced that will keep it from slipping sideways?

6. Feb 22, 2009

### pats6

I should be able to use arctan(v^2/rg) to give me the angle
when i plug the numbers in i get arctan(400^2/9.8*2100)=90
and that is not the right

7. Feb 22, 2009

### LowlyPion

400km/h = ??? m/s?

8. Feb 22, 2009

### pats6

400km/h= 1.1*10^-4
When i plugged it into the equation I got 3.3*10^-11 I dont think this is right because that angle is to small. Can u tell me what im doing wrong.
arctan((1.1*10^-4)^2/(9.8)(2100)

9. Feb 22, 2009

### LowlyPion

Gee, I get 111 m/s

400,000/3600 = 111.1111

10. Feb 22, 2009

### pats6

ok i used that and i get 90 degrees when i put it in as an answer it is declined im i still doing something wrong

11. Feb 22, 2009

### LowlyPion

I really think you need to recalculate your tan-1.