# Homework Help: How to calculate forces in a looping

1. Apr 3, 2006

### m0nki

needless to say I'm a physics-challenged person but as a designer, I'm finally confronted with the science part of life

I want to have an estimate-calculation on the forces that will act on a looping if I have an object of x kilograms moving at y speed hits a looping with z diameter.
I haven't got a clue where to start and trial/error testing is too expensive.

What I want to know is what formula's I can use in order to retreive the following info:
- minimum speed for object (object weight could vary) to complete the looping (different diameters)
- maximum diameter of looping for weight/speed combination
- forces that act on the looping's construction (in order to build a prototype)

think of it like an RC car doing 'Hotwheels" stunts ...

I appreciate any help with links, formula's, ...

2. Apr 3, 2006

### vanesch

Staff Emeritus
Well, what will help you is that the centrifugal acceleration of an object having a velocity v (in meters/second) on a track with radius R (meters) is given by v^2/R

Now, on top of the track, this centrifugal acceleration points upward of course, while the gravitational acceleration g points downward ; so if you want the thing to be sticking to the road, then you better have that v^2/R > g.

g = 9.81 m/s^2

3. Apr 4, 2006

### m0nki

thanks Vanesh !

do you know how I could use the centrifugal acceleration to calculate the force on the ramp/looping itself? I want to build a prototype but would like some insight on how tough I need to make the construction.
Also, I kind of expect that the object will not have a smooth transition from horizontal movement to the upwards looping, so is there a way to calculate the impact it will have if it 'hits' the looping-curve?

again, thanks for the input you already gave. I forgot how interesting this physics/math stuff is ... will pick it back up real soon.