Problem: Amar drives 16 km directly west from Upper East Side to Central Park at a speed of 90 km/h, then directly south 8.0 km/h to 7th Avenue at a speed of 80 km/h, then finally 34 km southeast to Madison Avenue at a speed of 100 km/h. All the roads were straight.
a. What was the change in velocity during this trip?
b. What was the average acceleration during this trip?
What equations do i use? Any help is appreciated.
I tried using A= Vf^2 - Vi^2 / 2d for each road stop, but I'm not sure if it's right.
If you use vector, the initial velocity is $(90,0)$, the final velocity is $(50\sqrt{2},-50\sqrt{2})$, since it is pointing southeast, hence positive in $x$ and negative in $y$. The change will be the difference of them.
Then the average acceleration should be the change of velocity divided by the total time spent.