Math question
Models: Two bicycles leave an intersection at the same time. One is headed due north at a constant speed of 10 miles per hour and the other is headed due east at a constant speed of 20 miles per hour. Express the distance [i]d[/i] (in miles) between the bicycles as a function of time [i]t[/i] (in hours). (Let [i]t[/i] =0 be the moment the bicycles leave the intersection.)
Simplify your answer.
HELP PLZ
September 28, 2014
1 Comment • Newest first
The person who is driving north will have a coordinate of (0,10t) while the person driving east will have a coordinate of (20t,0). These coordinates are relative to the intersection they both start on, which we can just assume to be (0,0). Now all you have to do is use the distance formula. d^2=(0-20t)^2+(10t-0)^2
d^2=400t^2+100t^2
d^2=500t^2
d=sqrt(500t^2)
d=sqrt(500)*sqrt(t^2)
d=sqrt(500)t
Therefore d(t)=sqrt(500)t