Question

Solve for r for the following:
r=2√5L
a) L=210
b) L=50
c) L=140

Answer 1

it is already solved for r, maybe you meant solve for L.

Answer 2

oops, here's the whole thing:
After an accident, police can estimeate the spped a care was traveling by measuring skid marks. The formula above can be used where r is the speed in mph and L is the length of the skid marks, in feet. Estimate the speed of a car that left skid marks:
a) 210 ft
b)50 ft
c)140ft

Answer 3

all you have to do is plug in all your choices and see you will get the speed

Answer 4

of each car

Answer 5

r is the speed, so just substitute the values in a), b), and c) for L and solve for r.
Here's the first one:
a) L = 210
r = 2*√5*210
r = 820√5