An advertisement claims that a particular automobile can "stop on a dime". What net force would actually be necessary to stop an automobile of mass 850kg traveling initially at a speed of 38.0km/h in a distance equal to the diameter of a dime, which is 1.8cm ?

Answer 1

Vo = 38km/h = 38000m/3600s = 10.56 m/s.

a = (V^2-Vo^2)/2d = (0-10.56^2)/0.018m =
6195 m/s^2.

F = m*a = 850 * 6195 = 5,265,920 N.

Maybe we shouldn't stop it on a dime!