- #1
jnimagine
- 178
- 0
Homework Statement
Two cars approach an intersection at the same time. The red car is 300m east of the intersection and traveling at a speed of 60km/h. The blue car is 450m north of the intersection and traveling at a speed of 75km/h. When are the two cars the closest?
Homework Equations
c^2 = a^2 + b^2
The Attempt at a Solution
I converted the speeds into m/s first then used it in a pythagorean theorem equation and found the derivative.
75km/h = 20.8m/s 60km/h = 16.7m/s
c^2 = (20.8t - 450)^2 + (16.7t - 300)^2
and when i do the derivative i get 20.2. But I was just wondering, does it make a difference whether i do 20.8t - 450 or 450 - 20.8t??