Question

The formula r=2√5L can be used to approximate the speed r, in miles per hour, of a car that has left skid marks of length L, in feet. How far will a car skid at 80 mph?

The car will skid ? feet.

Answer 1

is L under root

Answer 2

??

Answer 3

\[r = 2\sqrt{5L}\]
or, \[r = 2\sqrt{5}L\]

Answer 4

first one or second one

Answer 5

it looks like the first one.

Answer 6

ok
\[80 = 2\sqrt{5L}\]
\[\sqrt{5L} = 40\]
\[ 5L = 40^2 = 1600\]
\[L = 320 miles\]

now convert it into feets

Answer 7

IDK HOW TO DO THAT

Answer 8

CAN U JUST GIVE ME THE ANSWER

Answer 9

1 Mile= 5280 Feet
320 Miles x 5280 feet = 1689600 feet

Answer 10

it said 1689600 is wrong. :(

Answer 11

r=2 sqrt(5)L
80=2 sqrt(5)L
L=17.88854 miles
in feet 94451.511

Answer 12

it said 320 was the correct answer

Answer 13

i used the second equation so first must be the one,