Posted by Mike Joseph on .
A 1400 kg car rounds a curve of 57 m banked at an angle of 14 degree
If the car is traveling at 98 km/h, how much friction force will be required?
I cannot figure out how to solve this problem. Someone please help me?

Physics 
Elena,
ΣFy = N• cos θ − mg − f •sin θ = 0
ΣFx = N• sin θ + f •cos θ = m•v²/R,
where f –friction force
Solving the 1st equation for N, we obtain
N =( f •sin θ + m•g)/cos θ,
Substitute N to the 2nd equation and obtain friction force
f =m[(v²•cosθ/R)  g•sinθ].
f=1400[27²•cos14/57 – 9.8•sin18} =
=1400[12.42.04] =14000 N