RootMath

Hi Eric,

Welcome to the Forum! To answer your question:

Try not to think in terms of formulas. When working with vectors a nice picture can be very helpful (vectors are made to be drawn). Make sure you have a good understanding of vector basics. How do vectors add and subtract. What happens when we multiply a vector by a real number? If you have the grasp on that, then the last thing is: don't forget what you already know! If a train is moving 100km/h how long does it take it to travel 150km? If that's something you can solve then you can use the same method for vectors. If a train is traveling <100, 30>km/h how long does it take to travel <150,45>km?

Finally, if you are told that <x,y> is a vector and you are being asked to find x and y, then you're answer will be the vector <x,y>.



Now for a "walkthrough" of the question you posted:

Think of <200,375> as the position vector of the plane. That is, if we start from the origin and move 200km to the right and 375km up we will reach the plane. The same thing applies to Helicopter P, it's position is given by <-50,75>.

So for convenience well label the vectors (j for jet) J = <200,375> and P = <-50,75>. Now we want to find the vector that starts at P and goes to J, in other words we are finding the path the helicopter takes from P to J. The vector from P to J is simply equal to J-P. (see: ,6th video, Vector Subtraction).

So J-P = <200,375> - <-50,75> = <200 - (-50), 375 - 75> = <250,300>.

Alright, what we've done so far is figure out that Helicopter P needs to move <250,300>km in order to reach the plane. Well its moving <120,144> km/h, so if it flies for 1 hour then it will have moved exactly <120,144>km If it flies for 2hours it will have moved <240,288>km. But we need it to move <250,300>km, so its going to be flying for just over 2hours it looks like.

See if you can use that as a start. To finish this find exactly the time Helicopter P must fly in order to reach the plane. Then subtract 10 minutes and that will be the time that Helicopter A will be in the air. Use that information to find the position Helicopter A starts at.

Thank you very much for your explanation. I gave the problem another attempt and I was convinced I had it right, but the worked solutions I have disagree with me .
Either way, I think I can see what I was doing wrong. Thank you again!