Kinematics 1D ~ Lab. 4. What was the average speed of the truck for the six seconds? show your work here.

Transcription

1 Kinematics 1D ~ Lab Name: Instructions: Using a pencil, answer the following questions. The lab is marked based on clarity of responses, completeness, neatness, and accuracy. Do your best! Part 1: Graphing Truck Motion: In this section, you will be using the Lab Resources > Video: Moving Truck Data 1. Complete the following table with data from the video. Time (s) 0 Dist (m) 0 2. Please plot a position (y) verses time (x) graph on the grid provided (next page). Graph a best fitting smooth curve. Remember to be neat and tidy and label your axis. 3. What does the graph tell us about the speed of the truck? 4. What was the average speed of the truck for the six seconds? show your work here. 5. Sketch a rough graph (no units) showing what the position verses time graph would look like if: a) the truck was traveling a steady speed d t b) the truck was slowing down - include 3 tangent lines (refer to tutorials) showing 3 different speeds. d t Page 1 of 9

2 Hint: refer to the Submission Requirements Page 2 of 9

3 Part 2: Position vs Time Graphs (or D-t graphs): In this section, you will be using the Lab Resources > Media: Ramp n Roll Click "Edit," then manipulate the heights of the posts (drag the posts up and down), initial position (click the blue arrow left and right) and initial velocity (click the blue arrow left and right) as needed to address the questions below. 1. Set the initial position to 0 m and the initial velocity to 2 m/s. Check that the bottom of the graph states Position vs. Time a. Click Start and sketch the graph below. Label it a. b. Determine the slope of this graph. Be sure to include the units. Show work below. Page 3 of 9

4 2. Experiment with the simulation to determine answers to the following: a) What happens to the shape of the graph if you increase the Initial Velocity to 4 m/s. b) Describe what happens to the shape of the graph if you reduce the Initial Velocity to 0.5 m/s. c) Click on Edit and set the initial position to 200 m and the initial velocity to 2 m/s. Observe what happens carefully. How does changing the initial position affected the shape of the graph. d) Click on Edit and set the initial position to 200 m and the initial velocity to -2 m/s. Describe the affect this made of the graph. Summarize: Summarize how velocity and initial position are represented on a Position-time Graph. Put it all together: Without using the simulation make an accurate Position-time of a ball rolling on a flat surface with a constant velocity of -5 m/s and an initial position of 400m. Page 4 of 9

5 Accelerated Motion on a D-t Graph: 3. Click on Edit and set the initial position to 0 m and the initial velocity to 0 m/s. Check that the bottom of the graph states Position vs. Time. Now change it so that it slopes down to the right as shown below. a) Sketch the Position-Time graph below and label it a. (be sure to stop the sim once the ball has reached the 0.0 m mark) b) Describe the motion of the ball as it rolls down the ramp. Describe the ball s velocity, acceleration, and displacement using terms like positive, negative, increasing, or decreasing, c) Reverse the ramp so that it slopes down to the left. Set the ball s initial velocity to zero and initial position to 490 m (to ensure that it rolls down). Sketch the graph below and label it c. Page 5 of 9

6 4. Describe the ramp and motion that created the d-t graph below. a) Describe the motion (discuss velocity and acceleration): Use the words constant, increasing, decreasing, positive, or negative in your description. b) Sketch the ramp that made this graph and identify initial velocity and position v i = Initial position = Page 6 of 9

7 5. Describe the characteristics (sketch each graph) of a d-t graph that has: a) Constant positive velocity: b) Constant positive acceleration c) The initial velocity is positive but the acceleration is constant negative (a sketch of the graph will suffice) Now let s check your understanding with the Ramp and Roll Simulation: 6. Construct a ramp that has the ball moving with a constant, positive velocity. Sketch your ramp below and show your ball s initial position and velocity vector. 7. Construct a ramp that has the ball start with a constant negative velocity, then ends with a positive acceleration. Sketch your ramp below and show your ball s initial position and velocity vector. Page 7 of 9

8 Part 3: Displacement & Velocity Graphs: This simulation illustrates a man walking back and forth; his displacement graph is drawn as he walks. Your task is to construct a velocity graph and to find the relationship between the shapes of the displacement and velocity graphs. In this section, you will be using the Lab Resources > Media: Moving Person Use the simulation to create the d-t graphs shown below. In the spaces provided, record any initial values for d, v, and a. Sketch the v-t graph on the axis provided. d-t graphs Initial Settings d = v = a = v-t graphs d = v = a = d = v = a = Summarize: 1. Straight diagonal d-t graphs will become (shape?) v-t graphs. This means the man (is/is not?) accelerating. 2. Curved d-t graphs will become (shape?) v-t graphs. This means the man (is/is not?) accelerating. Page 8 of 9

9 Tip from the Teacher: Use the vertical grey slider to advance the man to any location on your graph. This will help you sketch the actual v-t graph. 3. Construct Velocity-time graphs from the d-t graphs below: a) b) c) Page 9 of 9