Explanation:
It is given that, the force needed to keep a car from skidding on a curve varies inversely as the radius of the curve and jointly as the weight of the car and the square of the car's speed such that,
mg is the weight of the car
r is the radius of the curve
v is the speed of the car
Case 1.
F = 640 pounds
Weight of the car, W = mg = 2600 pound
Radius of the curve, r = 650 ft
Speed of the car, v = 40 mph
k = 0.1
Case 2.
Radius of the curve, r = 750 ft
Speed of the car, v = 30 mph
F = 312 N
Hence, this is the required solution.
