The formular r= 2 cube root5L can beusedto approximate the speed r,in mile per hour,of a car that has skid marks of lenght L,in feet. How far will a car skid at 60 mph.

r = 2 (5)^(1/3) L

60 = 2(5)^(1/3) L
30 = (5)^(1/3) L
30 = 1.709975 L
L = 17.544 feet

Thank you Reiny for your help.

To find the distance a car will skid at 60 mph using the formula r = 2 * ³√(5L), we need to substitute the value of r with 60 and solve for L. Let's break it down step by step:

1. Start with the formula: r = 2 * ³√(5L).
2. Substitute r with 60: 60 = 2 * ³√(5L).
3. Divide both sides of the equation by 2 to isolate the cube root: 30 = ³√(5L).
4. Cube both sides of the equation to eliminate the cube root: 30^3 = (³√(5L))^3.
This simplifies to: 27000 = 5L.
5. Divide both sides of the equation by 5 to isolate L: 27000/5 = L.
This simplifies to: 5400 = L.

Therefore, a car skidding at 60 mph will skid approximately 5400 feet.