Describing Motion - 1/14/18

Summary: Motion is the change in position of an object over time. A scalar quantity measures the magnitude of something or the number that measures something. A vector quantity measures both the magnitude and the direction. Distance and displacement are examples of scalar and vector quantities. Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. While displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position. Speed and velocity are more examples of scalar and vector quantities. Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. Velocity is a vector quantity that refers to "the rate at which an object changes its position."

SP2 - Using Models: I used models and diagrams when practicing distance and displacement on the worksheets we completed in class. The models were used to help us understand displacement vs. distance and explained the world problem. An example is, "John flies directly east for 20 km, then turns to the north and flies for another 10 km before dodging a flock of geese. What was his displacement ?" The displacement is 22.4. I found this answer by using the Pythagorean theorem to find the hypotenuse of the triangle. You can see that 20 square plus 10 squared equals 500. So your answer is the square root of 500. However, this answer is incorrect because you need to include the units of measurement and direction since this is a vector quantity so the final answer would be 22.4 km north-east. As for the distance, you just add up the total miles traveled, in this case, 30 km.

XCC: Stability and Change: I have noticed stability and change relationships with speed and velocity. If you plot the speed that someone travels at when traveling to a location you can see how rate remains the same or stable or how they change due to events that could occur in real life. As you see in the graph above, the speed always changes. At the beginning of the journey, there is a steady acceleration. Then there is stability, the speed remains steady. Next, there's a gradual acceleration, a burst of speed. Finally, there's a steady deceleration. This shows me stability and change through different speeds which helps me understand motion more.