A 1200 kg car travels around a curve banked at 42.5 degrees in a circular path of radius = 150m, but the ramp is only 55m long. The force of friction on the car is 9000N, calculate the speed of the car.
radius = 150 m
θ (angle the incline makes with the horizontal) = 42.5
mass = 1200 kg
Friction = 9000 N
Fc= FNx + FFx
Fc= mv2 / r
The Attempt at a Solution
The car does not move in the y-plane, therefore:
Ff + Fg + FN = 0
FN = (mg + Ffsinθ)/cosθ
Solve for FN and I got 24213.83512 N
Then I used the value of FN to find FNx and added FFx to it.
Then I multiplied by the radius, divided by the mass and took the square root leaving me with 54m/s.
However, when I use the formula found on this page http://en.wikipedia.org/wiki/Banked_turn" [Broken] I got 67 m/s.
Which one is right? And If I'm wrong, where did I go wrong?
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