Answer the question.
-Police use a formula where S is the test-car speed and L is the test-skid length, to find the actual speed s in an accident which left a skid mark of l. Find the speed (nearest whole mph)when S = 45 mph,
L = 150 ft, L = 100 ft.
A)37 mph
B)55 mph
C)95 mph
D)68 mph

Question

Answer the question.
-Police use a formula  where S is the test-car speed and L is the test-skid length, to find the actual speed s in an accident which left a skid mark of l. Find the speed (nearest whole mph)when S = 45 mph,
L = 150 ft, L = 100 ft.
A)37 mph 
B)55 mph 
C)95 mph 
D)68 mph

Quizplus · Accepted Answer

We have two different values of L given in the problem.

For L=150ft: 
s = sqrt((S^2 * L)/(11 * L - 1.8 * S * sqrt(L))) 
  = sqrt((45^2 * 150)/(11 * 150 - 1.8 * 45 * sqrt(150)))
  = 55.14 mph
The nearest whole mph value is 55 mph.

For L=100ft: 
s = sqrt((S^2 * L)/(11 * L - 1.8 * S * sqrt(L))) 
  = sqrt((45^2 * 100)/(11 * 100 - 1.8 * 45 * sqrt(100)))
  = 37.97 mph
The nearest whole mph value is 37 mph.

Therefore, the best choice is B) 55 mph, as it is the answer for L=150ft.

Answer the Question. -Police Use a Formula Where S Is the Test-Car