practice

  1. Complete the worksheet on the first page of worksheet-compare.pdf. Fill each grid space with an appropriately concise answer.
  2. Work along with this example using worksheet-transform.pdf. The graph below shows velocity as a function of time for some unknown object.
     
    [magnify]
     
    1. What can we say about the motion of this object?
    2. Plot the corresponding graphs of displacement and acceleration as functions of time.
  3. Sketch the displacement-time, velocity-time, and acceleration-time graphs for …
    1. an object moving with constant velocity. (Let the initial displacement be zero.)
    2. an object moving with constant acceleration. (Let the initial displacement and velocity be zero.)
  4. The graph below shows the acceleration of a hydraulic elevator in a four story school building as a function of time.
     
    [magnify]
     
    The graph begins at t = 0 s when the elevator door closed on the second floor and ends at t = 20 s when the door opened on a different floor. Assume that the positive directions for displacement, velocity, and acceleration are upward. Determine …
    1. the maximum speed of the elevator
    2. the duration of the brief jerk experienced by the elevator centered on 17.5 s
    Sketch the corresponding graphs of …
    1. velocity-time
    2. displacement-time
    Determine …
    1. the most likely floor on which the elevator stopped

worksheets

  1. worksheet-graph-displace.pdf
    The worksheet for this exercise consists of three small and one large displacement-time graph.
    1. Complete the three small displacement-time graphs from the information provided below each graph.
    2. The larger displacement-time graph shows the motion of some hypothetical object over time. Break the graph up into segments and describe qualitatively the motion of the object in each segment. Whenever possible, calculate the velocity of the object as well.
  2. worksheet-graph-velocity.pdf
    The worksheet for this exercise consists of three small and one large velocity-time graph.
    1. Complete the three small velocity-time graphs from the information provided below each graph.
    2. The larger velocity-time graph shows the motion of some hypothetical object over time. Break the graph up into segments and describe qualitatively the motion of the object in each segment. Whenever possible, calculate the acceleration of the object as well.
  3. worksheet-choose-displace.pdf
    The graphs on the accompanying pdf show the displacement of a hypothetical object moving along a straight line. Choose the lettered graph that best represents each of the numbered descriptions. A graph may be used for more than one description or it may not be used at all. Some descriptions may correspond to more than one graph and some may not correspond to any graph at all.
  4. worksheet-choose-velocity.pdf
    The graphs on the accompanying pdf show the velocity of a hypothetical object moving along a straight line. Choose the lettered graph that best represents each of the numbered descriptions. A graph may be used for more than one description or it may not be used at all. Some descriptions may correspond to more than one graph and some may not correspond to any graph at all.

conceptual

  1. conceptual.pdf
    Sketch the displacement-time, velocity-time, and acceleration-time graphs for each of the following scenarios. (Be prepared to explain your sketches.)
    1. An elevator that ascends from the lobby to the 36th floor, stops, descends to the 27th floor, stops, and returns to the lobby.
    2. A basketball is dropped on the court and allowed to bounce up and down several times undisturbed.
    3. A car on a test track performing a zero-to-sixty acceleration test. (This acceleration will not be uniform.)
    4. A race between a tortoise and a hare that unfolds just like the fable of the same name. (An acceleration-time graph is not necessary for this particular problem.)
    5. Two cars are adjacent to each other on a four-lane highway. The first car accelerates uniformly from rest the moment the light changes to green. The second car approaches the intersection already moving and is beside the first car at the instant the light changes. It then continues driving with a constant velocity.
    6. Traffic lights on some streets are timed to facilitate traffic flow at a certain speed. Goofus and Gallant are stopped at a red light on this kind of street. When the light changes Goofus hammers the accelerator until he exceeds the speed limit. He arrives at the first light which is still red and stops. Gallant accelerates at a reasonable rate and never exceeds the speed limit. The second light turns green at just the right instant so that he never needs to brake at an intersection. Goofus and Gallant continue driving this way for three lights.

numerical

  1. The graph to the right

    [magnify]
    shows the altitude of a skydiver initially at rest as a function of time. After 7 s of free fall the skydiver's chute deployed completely, which changed the motion abruptly.
    1. Determine the velocity at the instant …
      1. just before the parachute opened.
      2. just after the parachute opened.
    2. What was the skydiver's acceleration …
      1. from the beginning of the jump to the time just before the parachute opened?
      2. from the time just after the parachute opened to the time when the skydiver landed?
    3. Sketch the corresponding graphs of …
      1. velocity-time.
      2. acceleration-time.
  2. The graph to the right

    [magnify]
    shows the velocity of a skydiver as a function of time. At time t = 0 s the skydiver is located at position y = 0 m at the door of the plane, at t = 8 s the parachute opened, and at t = 12 s the skydiver touched down. Assume that the positive directions for displacement, velocity, and acceleration are downward. Using this information sketch the corresponding graphs of …
    1. displacement-time.
    2. acceleration-time

statistical

  1. special-splits.html
    A split is a time at which the runner reaches a milestone distance in a race. In the 100 m dash, for example, split times are taken every 10 m. Splits for some of the world's fastest sprinters are given on the accompanying webpage. Fit a high order polynomial (fourth, fifth, sixth or higher) to the data for one of these athletes using a data analysis application. Determine the speed of your sprinter as a function of time by taking the derivative of this polynomial. Graph this new function and then analyze it.
    1. What were the runner's initial and final speeds?
    2. What was the runner's maximum speed and when did it occur?
    3. What was the runner's average speed?
    4. Did the runner's speed increase, decrease, or remain roughly the same near the end of the race?
    5. How well do you think this graph describes the actual performance of the runner? Are there any problem regions on the graph? How could the function be modified to improve the fit?
  2. jet-takeoff.txt, jet-landing.txt
    One fine day, a Boeing 717 departed from Mitchell International Airport (MKE) in Milwaukee. Approximately two hours later, it arrived at Laguardia Airport (LGA) in New York. During takeoff and landing, runway positions (in meters) were recorded as a function of time (in seconds) and the data were saved as tab-delimited text files. Using the data in these files and your favorite graphing software …
    1. construct a graph of distance vs. time for…
      1. takeoff and
      2. landing
    2. then add an appropriate curve fit so that you can determine …
      1. the acceleration at takeoff and
      2. the deceleration on landing
    3. and also determine …
      1. the final speed when the airplane left the runway in Milwaukee and
      2. the initital speed when the airplane hit the runway in New York

investigative

  1. The numbered streets in Manhattan above 14th Street are spaced apart such that twenty blocks equal one mile. Ride one of the local trains that runs beneath an avenue for at least five consecutive stations. Using a timer or a wristwatch record the starting and stopping times of the train and the street number of the station until you have reached the fifth station. Translate your data into a displacement-time and velocity-time graph. Include the necessary data tables. Use whatever units you wish. (This investigation can also be performed in other places in a car or a bus if the streets are gridded and you know the grid interval.)