When drawing vectors, what is the reference point?

Question

1) In order to have a vector quantity, what two things do you need to show?
2) What can you say about the slope of a line in a distance-time graph?
3) When calculating the area under a speed/time graph, what are you actually determining?

Answer 1

1. Direction and magnitude.

2. A speed -time graph that has a slope greater than zero shows an object accelerating, graphs that shows a straight means a constant speed is being kept, and a negative slope means the car is decelerating. The steeper the slope, the faster it is either accelerating or decelerating.

3. The area under the slope represents the total distance.

Answer 2

Your reference point is pretty much whatever makes the diagram easiest to 'see'. The only time it really matters is in a vector field where the magnitude (and direction) is a function of position.

1. Magnitude and direction
2. It's equal to speed.
3. Distance travelled.


Doug