# Newton's Second Law. Involving an airplane.

Tags:
1. Mar 12, 2015

### Trevor Mock

1. The problem statement, all variables and given/known data
An airplane goes into a turn 3.6km in radius. If the banking angle required is 28 degrees from the horizontal, what is the plane's speed?

2. Relevant equations
Newton's Second. The only forces acting on the plane are gravity and the normal force. This isn't given in the question, it is just obvious. Neglect friction.

3. The attempt at a solution
My main problem is drawing the free body diagram. I really need help with this problem. A clean, clear thorough explanation. Show every step please!

2. Mar 12, 2015

### Trevor Mock

The answer is 490km/h. I just don't know how to arrive at the answer.

Last edited: Mar 12, 2015
3. Mar 12, 2015

### collinsmark

Hello Trevor Mock,

Welcome to Physics Forums!

Are you sure you didn't leave something out of the problem statement, such as the the vertical component of the plane's acceleration (even if it happens to be zero)? (In other words, is the plane accelerating in the up or down direction? Or does it maintain a constant vertical component of velocity?)

Please read the "Guidelines for students and helpers" post at the top of this subforum (it's a sticky at the top of the Introductory Physics Homework subforum). It's you that must show your steps.

Anyway, some general guidance, list out all the forces acting on the plane. In this particular problem, two of those forces are important. The solution is possible once you make a particular assumption about the plane's vertical acceleration. You should be able to put the two important forces together, along with the "normal" force, to form a triangle.

Last edited: Mar 12, 2015