<PRE><B>Question 1047148</B>
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 care and the square of the speed.  
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F = k*(1/r^2)*W*(1/v^2) --- k = a constant, r = radius, v = speed
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Step 1, solve for k
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F = k*(1/400^2)*1200*(1/35^2) = 247
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Solve for k, then use k for the calculations.
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It 247-lb of force keeps a 1200-lb car from skidding on a curve of radius 400 ft. at 35 mph, what force would keep the same car from skidding on a curve of radius 850 ft. at 60 mph?  
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