How to Measure the radius of the arc

What one needs to perform the measurment process is a stiff metal measuring tape, a clinometer (something like the Suunto) and a plumb bob. You might also prefer to use string to measure the length of side C of the triangle. It could be fastened to the earth/asphalt. The three things one has to do is determine the length of side C, the angle (A) from the horizon down to where the endpoint of side C is and the distance (h) from the top of side c to the earth at the peak of the arc. I found this easier using an old camera tripod. My plumb bob went down through the center of the tripod giving me a straight line and a place on which to aim my clinometer from. Of course if you have a $10K electronic measuring system just forget the latter.

The speed at which a vehicle will lift off the surface while traversing a crest of a hill or other arc shaped object (ie. certain bridges) is :

This formula is derived from: