posted by Ray .
The parachute on a race car of weight 8,810 N opens at the end of a quarter-mile run when the car is traveling at 34 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1,100 m?
V^2 = Vo^2 + 2a*d.
a = (V^2-Vo^2)/2d.
a = (0-(34)^2)/2200 = -0.525 m/s^2.
m*g = 8810N.
m = 8810/9.81 = 899 kg = Mass of car.
F = m*a = 899 * (-525) = -472 N.