Calculus
posted by Robin .
Two cars start moving from the same point. One travels south at 60 mph and the other travels west at 25 mph. At what rate is the distance between the cars increasing 2 hours later?
Let x = the distance covered by the south traveling car.
Let y = the distance covered by the west traveling car.
Let z = the distance between the cars.
In this problem you are given two rates. What are they? Express your answers in the form dx/dt, dy/dt, or dz/dt = a number. Enter your answers in the order of the variables shown; that is, dx/dt first, dy/dt, etc. next.
What rate are you trying to find?
Write an equation relating x and y . Note: In order for WeBWorK to check your answer you will need to write your equation so that it has no denominators. For example, an equation of the form 2/x = 6/y should be entered as 6x=2y or y = 3x or even y  3x = 0.
Use the chain rule to differentiate this equation and then solve for the unknown rate, leaving your answer in equation form.
Substitute the given information into this equation and find the unknown rate. Express your answer in the form dx/dt or dy/dt = a number.

x = 60t
y = 25t
z = √(x^2+y^2) = 65t
All that chain rule stuff is irrelevant here, since dz/dt = a constant.
Respond to this Question
Similar Questions

math
two cars leave town at the same time. one travels west at 56 mph, and the other travels south at 42 mph. after one hour, how far apart are the cars? 
calculus
Q#1: From a point of O, two cars leave at the same time. One car travels west and after âtâ sec, its position is x=t2+t ft. the other car travels north and it covers y= t2+3t ft in âtâ sec. At what rate is the distance between … 
11th grade Math
Two cars travel the same distance. The first car travels at a rate of 37 mph and reaches its destination in t hours. The second car travels at a rate of 54 mph and reaches its destination in 3 hours earlier than the first car. How … 
Calculus
Two trucks start from the same point. One truck travels due east at a rate of 50 mph and the other trucks travels due north at a rate of 60 mph. At what rate is the distance between the two vehicles increasing 1 1/2 hours later? 
calculus
Two cars start moving from the same point. One travels south at 28mi/h and the other travels west at 50mi/h. At what rate is the distance between the cars increasing 4 hours later? 
calculus
Two cars start from the same point at the same time. One travels north at 25 mph, and the other travels east at 60 mph. How fast is the distance between them increasing at the end of 1 hr? 
Calculus
Two automobiles start from a point A at the same time. One travels west at 60km/hr and the other travels north 35 km/hr. how fast is the distance between them increasing 3hr later? 
Calculus 1
Related Rates Problem: Two cars start moving from the same point. One travels south at 40 mi/h and the other travels west at 30 mi/h. At what rate is the distance between the cars increasing three hours later? 
Lee college
two cars start driving in the same direction from the same place. If one travels 54 mph and the other 61 mph, how long will it take to be 49 miles apart? 
Calculus
Two planes leave an airport simultaneously. One travels north at 300 mph and the other travels west at 400 mph. How fast is the distance between them changing after 10 minutes?