What does a positive and negative slope represent for a velocity versus time graph?

The velocity versus time graph has 2 quadrants, positive and negative. Positive velocity is one direction and negative is the other way- often positive will be to the right of the x axis and negative to the left. - +

For positive velocity, if the slope is positive, it is speeding up. Over time, the velocity is getting larger (which is acceleration). If the slope is zero flat on the x axis, the object is not moving and has a velocity of 0. If the slope is flat on ex. 4.5 m/s, then the object is at a constant velicty of 4.5 m/s. The object is staying at the same velocity, not going faster or slowing down. If the slope is negative, the object is slowing down.

For negative velocity, if the slope is negative and moving away from 0 velocity, the object is speeding up. The velocity is getting larger over time, the negative is signifying direction not amount. Really important concept that blew my mind. Slope is positive, the velocity is getting closer to zero- it is slowing down. Flat on -4.5 m/s, it has a constant velocity.

One way to look at v vs t graphs is how the velocity is in relation to zero. Moving away from zero, speeding up. Moving closer, slowing down. Staying same distance from zero, constant velocity. This is probably the most important paragraph.

Good luck with Physics!

c)as speed changes, wavelength and frequency change.

everything changes!