please help its urgent...

[Guest]

A car traveling at a rate of 30 ft/sec is approaching an intersection. When the car is 120 ft from the intersection, a truck traveling at a rate of 40 ft/sec crosses the intersection. If the roads are at right angles to each other and the truck leaves the intersection after 2 seconds, how fast are the car and the truck separating when the truck leaves the intersection?

 

[crestu]

Hey bobby,

Give these steps a go:

1. Draw a diagram
2. Find a relationship between the positions of the vehicles and the distance between them
3. Implicitly differentiate with respect to time
4. Substitute in known values

If that doesn't work, post whichever step you are having difficulty with and I'll try and explain that step to you.

crestu