Physics problem?

Question

At what minimum speed must a roller coaster be traveling when upside down at the top of a circle so that the passengers will not fall out? Assume a radius of curvature of 9.4 m.

Answer 1

The inward (downwrd) acceleration must be exactly 'g' for the passengers to JUST not fall out. That means that:

v^2 / r = g, where 'r' is the radius of curvature.

So, in this case, v^2 = g r = 9.81 m/sec x 9.4 m.

Therefore, v^2 = 92.214 m^2/sec^2, so that v = 9.603... m/sec, to this number of significant figures.

Live long and prosper.