Question

Pairs of markings a set distance apart are made on highways so that police can

detect drivers exceeding the speed limit. Over a fixed distance, the speed R
varies inversely with the time T. In one particular pair of markings, R is 59 mph
when T is 4 seconds. Find the speed of a car that travels the given distance in 5
seconds.

Please answer!!!

Answer 1

R = k(1/T) = k/T

when R = 60, T = 8

60 = k/8

k = 480

R = 480/T

so when T = 6

R = 480/6 = 80 mph