How Fast is the Roller Coaster Car at the Top of the Hill?

[hbteen]

Homework Statement

As a roller coaster car crosses on the top of a 10 m radius hill (the track is underneath the car), its apparent weight is one-half its true weight. What is the car's speed at the top?

Homework Equations

A=v^2/r
F=ma

The Attempt at a Solution

I tried saying the weight was .5 and solving for velocity, but I still have a missing # for the Force variable.
Where do I go from there?

 

[tiny-tim]

Welcome to PF!

Hi hbteen! Welcome to PF!

As a roller coaster car crosses on the top of a 10 m radius hill (the track is underneath the car), its apparent weight is one-half its true weight. What is the car's speed at the top?
…
A=v^2/r
F=ma
…
I tried saying the weight was .5 and solving for velocity, but I still have a missing # for the Force variable.

The weight doesn't matter … it cancels out.

Show us what you tried, and then we'll see where the problem is.