A swimmer enters the water and swims in a straight line at 54 meters per minute. Another swimmer enters the water 3 minutes later, swimming in the same direction at 134 meters per minute. Which parametric equations could model the swimmers' paths from the time the first swimmer entered the water?
Answer
A
x(t) = 54t and y(t) = 134(t – 3)
B
x(t) = 54(t – 3) and y(t) = 134t
C
x(t) = 54(t + 3) and y(t) = 134t
D
x(t) = 54t and y(t) = 134(t + 3)
Explanation
Let t be the number of minutes since the first swimmer entered. The first swimmer travels 54t meters. The second swimmer starts 3 minutes later, so by time t they have swum for t − 3 minutes and traveled 134(t − 3) meters. Choice A gives those two distances: x(t) = 54t and y(t) = 134(t − 3).
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