Calculations for Crash Test Trailer

[mncad]

Working on a side project helping a 4H group and I need some help. Building a trailer with a "car" that will slide down an incline that is about 14' long using only gravity and crash into some rubber stops at the end. The "car" will just be on casters holding 2 car seats with small dummies. Trailer is used at fairs and such to demonstrate that you need to wear your seat belt. I would like to simulate a 15 mph crash. I need a formula to determine the slope of the incline. Any help would be greatly appreciated.

Thanks,
mncad

 

[mirekp]

It is little bit based on the mechanism design (friction), but with good approximation you can use the formula for free fall.
H=v^2/(2*g) where
H…required high
v…speed
g…gravitational constant

Then H=22^2/(2*32,16)=7,5

The angle is then the arctan(7,5/14) =28 deg

Mirekp

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Mechanical calculations