SOLUTION: two cars leave a crossroads at the same time. One heads north at 50km/h and the other heads east at 70km/h. How far apart art the cars after 0.5h? After 2h?

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Question 338490: two cars leave a crossroads at the same time. One heads north at 50km/h and the other heads east at 70km/h. How far apart art the cars after 0.5h? After 2h?
Found 2 solutions by mananth, fractalier:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
two cars leave a crossroads at the same time. One heads north at 50km/h and the other heads east at 70km/h. How far apart art the cars after 0.5h? After 2h?
..
it means that they are taking a right angle path.
+Distance+=+rate+%2A+time
car 1 rate = 50km/h
time = 0.5 hours
Distance = 50*0.5 = 25 km.
..
Car 2 rate = 70km/h
distance = 70*0.5 = 35km.
35 km and 25 km are the legs of right triangle
35%5E2%2B25%5E2=+D%5E2
1225+625=D^2
D%5E2=1850
+D+=+sqrt%281850%29
D= 43.01 km.
..
repeat the same for 2h time

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
If you make yourself a diagram, you'll notice that the distances represented by the car's travels are the sides of a right triangle...their distance at any time can be found using the Pythagorean Theorem.
Now remember, rate times time equals ditance...
After .5 hours, the north side is 25 km, and the east side is 35 km.
Now apply a^2 + b^2 = c^2 and find c.
We get c^2 = 25^ + 35^2 = 625 + 1225 = 1850
c = sqrt(1850) = about 43 km
Now repeat the procedure for two hours travel...see if you get c = 172 km...