Expert: Paul Soderman - 9/10/2002

Question
Given: A golfer putts a ball 18.0 ft at 60 degrees north of east, and then putts the ball 6.0 ft at 20 degrees west of north.  The second putt puts the ball into the hole.

Required: Determine the distance and angle a single putt would have to go from the starting point to get into the hole.  Sovle the problem both graphically and trigonometrically.


I have tried so many different ways to work this question that I have confused myself.  I believe that it would need to go 24ft.  The angle has me confused. Could you please help me.  I would greatly appreciate it.  Thanks  

Answer
Courtney

I don't usually do homework problems, but this is simple vector summation, so I had a go.

The first vector is 18 cos60 i + 18 sin60 j
The second is 6 sin(-20) i + 6 cos(-20) j

The resultant is the sum of the two for which I got
6.95 i + 21.23 j

The magnitude is 22.34 and the angle is 71.9 deg north of east.

Hope that's right.

Paul