Person in cart traveling down a valley

[redworld33]

Homework Statement

A 60 kg person rides in a 20 kg cart
moving at 13 m/s at the bottom of a valley that is in the shape of an arc of a circle
with a radius of 36 m. What is the apparent weight of the person as the cart passes
the bottom of the valley?

Homework Equations

F=ma
F=(V^2/r) * (m1 + m2)

The Attempt at a Solution

Fnet = Fn - Fg
m(V^2/r) - mg
80(169/36) - 80(9.8)
= -408.44
...im stuck. I don't feel like this is right and I don't know where I really went wrong

 

[jackarms]

You have the right equations and all, but take a step back for a second. In the context of the problem, what does apparent weight represent? What quantity represents it?