Finding the radius of an arc

1. Mar 28, 2009

jelynell

1. The problem statement, all variables and given/known data
Im having trouble figuring out which equation to use for this problem. The problem states: "Consider a pilot at the lowest point of a circular arc banking upward. Find the tightest radius arc that an untrained individual can fly ( a total of +5 G, G standing for the normal force the accelerating aircraft is exerting on the pilot. For example, 6G force would be exerting a normal force 6 times the persons weight.). They are traveling at 700m/s.

2. Relevant equations
Since this involves normal force, I thought I could somehow use: the sum of F=ma and Fw=mg
In addition I tried using a=v squared/r and/or v=2(pi)r/T

3. The attempt at a solution
In an attempt to try to solve this problem I tried using Fn= 5N in the equation Fn-Fw=ma By finding acceleration I could then use a=v squared/r to solve for r, but I dont have enough variables to plug in to the first equation.
So I tried using v=2(pi)r/T giving me 700m/s=2(pi)r/T so then I could find r this way, However I do not know the value for T.
Am I using the completely wrong equations? If not, what am I doing wrong?

2. Mar 28, 2009

LowlyPion

Welcome to PF.

I'd suggest drawing a diagram and making sure how much acceleration the plane will impart and how much is just a result of gravity.

As to your equation, you want to consider the centripetal acceleration here.

3. Mar 28, 2009

Delphi51

I think you have it here. r = v^2/a
Your acceleration is 5 times 9.81.