1. The problem statement, all variables and given/known data Amy is traveling at 60mph on the highway, due North. The on-ramp nearby starts out going West, and then curves around so that eventually it is also North, parallel to the highway. A) Bob appears, traveling 40mph going West (on the onramp). What is his speed relative to Amy? B) In the next moment, he is heading due Northwest, now going 50mph. What is his speed relative to Amy now? C) Finally, he is in the Northward position, and is accelerating to 55mph. What is his speed relative to Amy now? 2. Relevant equations I think this involves some basic trig to calculate the vector components / actual vectors. 3. The attempt at a solution So I am a little fuzzy on the whole relative velocity when objects are moving towards eachother at angles. For the last part, (C), I believe it would be 5mph, because relative to her speed, he is going 5mph slower that she is. I attempted part (A) by setting up a right triangle where the Y-Component is 60mph, the X-Component is 40mph, and solved for the resultant vector, which yielded √602 + 402 = 72.1 mph. I am not entirely sure if this is even the correct approach however. For part (B), I am a little confused about how exactly the diagram should look like. All I know is that Northwest would be 45°, but I don't how the triangle itself would look.