Question 243615
Two cars leave a city at noon. One car travels north and the other travels east.
 Suppose the northbound car is traveling at 60 mph, and the eastbound is traveling at 50 mph.
:
This is a pythag problem, distance between the cars is the hypotenuse: a^2 + b^2 = c^2
n = no. of hrs traveled; a = 50n; b=60n
:
 Make a table to show the distance between the 2 cars at 1 hour, 2 hours, 3 hours and "n" hours.
1 hr: {{{sqrt(50^2 + 60^2)}}} = 78.1 mi
2 hr: {{{sqrt((50*2)^2 + (60*2)^2)}}} = 156.2  mi
3 hr: {{{sqrt((50*3)^2 + (60*3)^2)}}} = 234,3 mi
n hrs {{{sqrt((50n)^2 + (60n)^2)}}} = {{{sqrt(6100n^2)}}} mi
:
 Then, suppose that the northbound car is traveling at 40 mph and after 2 hours, the two cars are 100 miles apart.
 How fast is the other car going?
Let a = 40*2, c=100, find b
80^2 + (2b)^2 = 100^2
6400 + 4b^2 = 100^2
4b^2 = 10000 - 6400
4b^2 = 3600
b^2 = {{{3600/4}}}
b^2 = 900
b = {{{sqrt(900)}}}
b = 30 mph is the 2nd car
;
:
Check on a calc: enter {{{sqrt(80^2 + 60^2)}}} = 100 mi