Question 329320
Ok, here's the equation:
Let F = Force required to keep car from skidding.
Let W = Weight of car in lbs.
Let S = Speed of car in mph.
Let r = Radius of the curve in feet.
Let k = the constant of variation.
{{{F = (W*(S)^2/r)*k}}} First, find the value of k.  Substitute the given values of: F = 3600 lbs, W = 1800 lbs, S = 20 mph, and r = 600 ft.
{{{3600 = (1800(20)^2/600)*k}}} Evaluate.
{{{3600 = ((1800*400)/600)*k}}}
{{{3600 = (1200)*k}}} 
{{{k = 3}}} Now thw equation becomes:
{{{F = (W*(S)^2/r)*3}}} Now substitute the problem values of: W = 1800 lbs, S = 50 mph, and r = 570 ft.
You can work this out. 
I got F = 23,684.2 lbs.