The force (in pound-force) needed to keep a car from skidding on a curve…
2023
The force (in pound-force) needed to keep a car from skidding on a curve varies directly with the weight of the car (in pounds) and the square of its speed (in miles per hour [mph]) and inversely with the radius (in feet) of the curve. Suppose 6125 pound-force is required to keep a 2750 pound car, travelling at a speed of 35 mph, from skidding on a curve of radius 550 feet. How much pound-force is then required to keep a 3600 pound car, travelling at a speed of 50 mph, from skidding on a curve of radius750 feet?
- A.
11960
- B.
12150
- C.
12240
- D.
12000
Attempted by 11 students.
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Correct answer: D
The force varies directly with weight and speed squared, and inversely with radius: F = kWv^2/r. From the first case, k = 1. For the second case, F = 3600 x 50^2 / 750 = 12000 pound-force.