Kinematics!

We have learned so much about physics so far! We learned about relative motion last week and now we are talking about position, distance, displacement, speed, and velocity! We learned that position is where something is and distance is a scalar quantity referring to  how far away something is. Displacement is a vector quantity referring to how far out of place something is. For example, my dog, Hoku! She likes to play in the grass, running around in circles, and sometimes running after cats. When she goes outside, she leaves her shade under the tree and runs in circles (not doing many laps, shes kind of chubby), then stops and returns to her spot in the shade. Although her distance traveled may be high, her displacement is zero. This is because displacement refers to how far out of place she went. She started sitting under her shade and after finishing her workout, she returned to the exact spot she was in.

We also learned about velocity. Velocity is a vector quantity that refers to "the rate at which an object changes positions. Let's use Hoku for another example. When she runs for fun, let's say she runs at about 8 mph. But when she sees a cat and shes determined to chase it, she runs at a much faster speed, maybe 20 mph. If we were to graph this, we would find that the slope of the line for Hoku chasing the cat would be steeper than the slope of  her casual run. In class, we learned the first graphing rule:

"The slope of a position vs. time graph is velocity"

Because we know that velocity is the slope of a position vs. time graph, we can conclude that when Hoku is chasing a cat, she has a higher velocity than when she is going on a casual run.