At t=0, they are both 10 kms from their intersection.
Think Pythagoras. Let D=square of distance between ships.
A ship P is travelling due East at 30 km/h and a Ship Q is travelling due South at 40 km/h.
Both ships keep constant speed and course. At t=0 they are each 10 km from the point of intersection of their courses and moving towards the point.
Iv found the co-ordinates of Q relative to P at t=0
---->X=(10,10)km
iv also found the velocity of Q relative to P----> V= V[Q] -V[P]
-----.V= (0,40) - V(30,0)
----- V= (-30,40)km/h
but im struggling to find the time at which P and Q are closest to each other...is there anyone that can help??? thankz
thankz...but i was wondering if i did the first part right that i showed?(shown below) because im not too sure if i was meant to include negative signs with any of the answers? can u please just check that for me thankzOriginally Posted by galactus
Iv found the co-ordinates of Q relative to P at t=0
---->X=(10,10)km
iv also found the velocity of Q relative to P----> V= V[Q] -V[P]
-----.V= (0,40) - V(30,0)
----- V= (-30,40)km/h
Hello, dopi,Originally Posted by dopi
with your problem you use automatically a coordinate system: The pos. x-axis points to East and the pos. y-axis points to North.
At the time t = 0 the ship P is at P(-10, 0) and the ship Q is at Q(0, 10). The movement of both ships is described by a straight line. The speed is described by a vector:
Thus P is moving along the line:
and Q is moving along the line:
The distance between the ships is:
I don't understand why you want to calculate the relative coordinates. It isn't necessary with your problem.Originally Posted by dopi
This was already done by galactus.Originally Posted by dopi
Greetings
EB
Hello, dopi!
You seem to be using a coordinate system and vectors
. . and I don't know what you plan to do with them.
galactus gave you the solution . . . so why struggle with your approach?
I'll make some diagrams to accompany his excellent solution.
Originally Posted by galactusCode:* Q | | | 10 | | | P * - - - - - - - - o 10
hours later, has moved km east to point
. . and has moved km south to pointAnd we want to minimize the distanceCode:* | | 40t | o B | | 10-40t * - - - o - - - - * 30t A 10-30t
Originally Posted by galactus