Scalar and vector
Scalar quantities are quantities that are measured by magnitude or some sort of numerical value alone. An example of a scalar quantity is 109 mph. Scalar quantities can be how big, how fast and how quick.
Vector quantities are quantities that are measured by a numerical value and a distance. An example of a vector quantity is 27 km/min NE. direction can be right, left, up, down, north, south, east, west, etc. If there is no direction, it is not a vector quantity.
Reference Points
Reference points can be anything. A tree, a rock, your couch, the bus that just passed your car. Reference points can decide whether you are moving or not.
If the distance between you and your reference point changes, than you are moving. If you were sitting still in your car and the reference point was your seat, you would not be moving. However, if the reference point was a tree in a yard your car passed, than you are moving. Your car passed by the tree, and the distance between the car and the tree is changing, so even though you sit still in your car, you are moving relative to the tree.
Distance and Displacement
Distance is kind of an easy concept to get. You walk two miles south, get in your car and drive 10 miles west. What is your distance from your starting point? Twelve miles. But displacement is a little bit harder to understand.
Distance can be moving straight or turning. You start at your house, walk three blocks, turn left and walk four blocks to get to your friend’s house. Displacement starts at the same origin (beginning) but it travels in a straight line. While distance is a scalar quantity (numerical values only), displacement is a vector quantity, meaning that the displacement is written incorrectly if there is no direction in the answer. Based on the question above, what is your displacement?
If you walked three steps forward, three steps left, three steps back and three steps right, you would end up at your starting point. Your distance would be equal to twelve steps, but your displacement is equal to zero because you moved back to your starting point (origin).
S&EP: SP5 Using Mathematics
I used math (ex: the pythagorean theorem) to calculate distance and displacement while completing the formatives this week. Math is useful in this case because it helps you calculate a faster way to get places. In the google map example, we can see how math is useful to find the distances between places. If you were going around museums and ended up in the place you started at, you displacement would be zero, no matter what your distance.
XCC: Structure and Function
This structure (the model) works very well. It is a visual representation of distance in displacement. While not to scale, it is still useful. The function of this model is based on its structure. If you draw the model wrong, you won’t be able to use it and may end up with an answer that is completely wrong. The mistake could be putting the lines in wrong and saying that the displacement is going in a different direction than it actually is. It could be calculating the displacement incorrectly and ending up with the wrong numerical values. Whatever the case, building the structure of this model correctly directly impacts its function as a tool.
No comments:
Post a Comment