Linear Motion Web Quest Vectors and Scalars Khan Academy: Intro to Vectors and Scalars 1. What is a vector quantity? 2. Give an example of a vector quantity. 3. What does “magnitude” mean? 4. What is a scalar quantity? 5. Give an example of a scalar quantity. Displacement Khan Academy: What is displacement? 1. What does it mean when we say we have to define position relative to a reference frame? (Explain and give an example.) 2. Which variables are usually used to represent the horizontal position and the vertical position? 3. What is displacement? 4. What could be an equation for displacement in the x-direction? 5. What could be an equation for displacement in the y-direction? 6. What does the triangle symbol mean? explain. 7. Is displacement a vector or scalar? Explain. 8. Show an example calculation of displacement. ( show: diagram, variables defined (with units), formula, numbers plugged in, answer with units). 9. Explain the meanings of positive and negative displacements. 10. How is distance different from distance travelled? Explain. 11. Scroll down to the section titled “What do solved examples involving displacement look like?” on this webpage. a. Sketch and show one worked example of displacement. b. Sketch and show one worked example of distance traveled. Velocity and Speed Khan Academy: What is velocity? 1. What is average velocity? 2. What is a formula for average velocity? 3. Show an example calculation of average velocity. (show: diagram, variables defined (with units), formula, numbers plugged in, answer with units). 4. What is instantaneous velocity? 5. How is instantaneous velocity different from average velocity? Explain. 6. What is instantaneous speed? 7. What is average speed? 8. How is instantaneous speed different from average speed? Explain. 9. Explain the example given in Figure 2 in your own words (picture showing home and store). 10. Figure 3 shows three graphs for the round trip to the store shown in Figure 2. a. Sketch and label all three graphs. b. Explain why the velocity vs. time graph looks different from the speed vs. time graph. Position vs. Time graphs Khan Academy: What are position vs. time graphs? 1. What goes on the vertical axis? 2. What goes on the horizontal axis? 3. Try the sliding-dot interactive graph. a. What is the position at t=4s? b. What is the position at t=7s? 4. What does the slope of a position vs. time graph represent? 5. What is the equation for finding the slope on a position vs. time graph? 6. Try the sliding-dot interactive graph that shows the slope (red line). a. During what time interval(s) is the object moving in the positive direction? Explain. b. During what time interval(s) is the object moving in the negative direction? Explain. c. Is the object ever at rest during during the whole time interval of 10s? If so, when? Explain. d. When is the object moving with the highest speed? Explain how you can tell from the graph. Velocity vs. Time graphs Khan Academy: Velocity time graphs (& acceleration) 1. What animal is featured in this video? 2. What goes on the vertical axis? 3. What goes on the horizontal axis? 4. The narrator compares the velocity time graph to a speedometer. a. What is the same about the graph and the speedometer? b. What does the graph tell you that the speedometer can’t? 5. How does the velocity time graph give the direction of motion? 6. How does the graph show the speed of the animal is increasing? 7. What color is the featured animal? 8. What do we call it when objects change their speed and/or direction? 9. In the video, the narrator finds the slope of the velocity time graph. What quantity does the slope represent? 10. Show one example calculation of acceleration from the velocity time graph (show: diagram, variables defined (with units), formula, numbers plugged in, answer with units) 11. What is “uniformly accelerated motion”?
