1. ## Vehicle travelling question

a vehicle , say A, starts 13km north of an intersection and proceeds due south at 50kph. Another vehicle, say B, starts 8km east of the intersection and proceeds due west at 40kph.

A) find equasions for the y coordinate of the first vheicle and the x coordinate of the second vehicle
B)find an expression for the square of the distance between the two vehicles. differentiate both sides
C) solve for ds/dt=0 and show minimum distance occurs at just under 15 mins fromt=0
D) find distance at this time
e)find the rate of approach at time t=.1hours

what do i need to do?

2. Originally Posted by jimmy12345
a vehicle , say A, starts 13km north of an intersection and proceeds due south at 50kph. Another vehicle, say B, starts 8km east of the intersection and proceeds due west at 40kph.

A) find equasions for the y coordinate of the first vheicle and the x coordinate of the second vehicle
Assuming that the y-coordinate is given by the distance in km north of the intersection (which is not said in the problem), for A, y= 13- 50t where t is the time in hours after this starting time. With similar assumptions about the x-coordinate, x= 8- 40t.

B)find an expression for the square of the distance between the two vehicles. differentiate both sides
Pythagorean theorem!

C) solve for ds/dt=0 and show minimum distance occurs at just under 15 mins fromt=0
D) find distance at this time
e)find the rate of approach at time t=.1hours

what do i need to do?

3. may see stupid but im stuck on part c

4. anyone?