Disturbed by speeding cars outside his workplace, Nobel laureate Arthur Holly Co
ID: 2176173 • Letter: D
Question
Disturbed by speeding cars outside his workplace, Nobel laureate Arthur Holly Compton designed a speed bump (called the "Holly hump") and had it installed. Suppose a 1 800-kg car passes over a hump in a roadway that follows the are of a circle of radius 20.8 m as in the figure below. If the car travels at 25.0 km/h what force does the road exert on the car as the car passes the highest point of the hump? magnitude N direction What is the maximum speed the car can have without losing contact with the road as it passes this highest point? km/hExplanation / Answer
a)
25.0 km/h = 25.0 * 10^3 m / 3600s = 6.944 m/s
Fn = mg - mv²/R
Fn = m(g - v²/R)
800kg (9.80 - 6.944²/20.8)
Fn = 5985.4 N (upwards)
b)
mg = mv²/R
v² = Rg
20.8m x 9.80 = 203.84(m/s)²
v = 203.84 = 14.27 m/s