SOLUTION: 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 ti

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Question 232767: 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 time T. In one particular pair of markings, R is 45 mph when T is 6 seconds. Find the speed of a car that travels the given distance in 5 seconds.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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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 time T.
In one particular pair of markings, R is 45 mph when T is 6 seconds.
Find the speed of a car that travels the given distance in 5 seconds.
:
Speed varies inversely with time so we can write an inverted ratio equation, find r
5%2F6 = 45%2Fr
Cross multiply
5r = 6 * 45
:
5r = 270
r = 270%2F5
r = 54 mph if he passes the markers in 5 sec