Vertical Circles Centripetal Acceleration

[Pedgepoke]

Homework Statement

A jet pilot takes his aircraft in a vertical loop. V is 840 km/hr (233.3 m/s) find the min. radius of the loop to that the centripetal acceleration at the bottom does not exceed 6 Gs.

Homework Equations

a = v^2 / r
F = ma

The Attempt at a Solution

I don't know where to start. Confused about the Sum part (Fx and Fy)

 

[kuruman]

Start by drawing a free body diagram of the pilot at the bottom of the circle.

On edit: Actually you don't need the FBD. What is an expression for the centripetal acceleration? Hint: It's one of the relevant equations.