| 
 
 
| Question 5042:  If two planes leave the same airport at 1:00 PM, how many miles apart will they be at 3:00 PM if one travels directly north at 150 mph and the other travels directly west at 200 mph?
 Answer by Earlsdon(6294)
      (Show Source): 
You can put this solution on YOUR website! Plane A travels due north at 150 mph for 2 hours, it will go 300 miles. Plane B travels due west at 200 mph for 2 hours, it will go 400 miles.
 Draw the two vectors and you will see that they make two sides of a right triangle.  The distance between the two planes at the end of two hours is just the hypotenuse of this triangle.
 You could use the Pythagorean theorem (c^2 = a^2 + b^2) to find the distance...or you could recognise that 300 and 400  are two of a pythagorean triplet (300, 400, 500) and the third number of this triplet is 500.
 So, the planes will be 500 miles aprt at the end of two hours.
 | 
  
 | 
 |