I got all the other centripetal force questions but this one has me stumped...(adsbygoogle = window.adsbygoogle || []).push({});

As a roller coaster car crosses the top of a 30m-diameter loop-the-loop, its apparent weight is the same as its true weight. What is the car's speed at the top?

The formula I used for all of the other questions was F=mv^2/r. The problem is the only number I have is the diameter (therefore radius). I'm guessing because the apparent weight is the same as true weight the net force is zero? There's also no way to get mass. Maybe there's another formula? Any assistance with this problem would be much appreciated!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Centripetal force of a roller coaster car

**Physics Forums | Science Articles, Homework Help, Discussion**