/ Name______
Use Logger Pro to analyze the motion of a ball rolling off of a table and flying through the air.
1 Follow your teacher’s directions to save the movie titled “Galileo’s Projectile” to your computer so that you can use Logger Pro to analyze the motion.
2 Open Logger Pro, click on the “Insert” tab and click on “Movie…” Now navigate to the location you saved the video titled “Galileo’s Projectile”.
3 Follow the directions for “Performing Video Analysis in Logger Pro” on the provided sheet to analyze the motion of the ball on and off the table. Make sure to do step #7, setting the scale in the video.
Note: Right-clicking on the y-axis variable allows you to change the type of graph that is displayed. See the image to the right.
4 Record the horizontal position versus time graph (x vs. t) for the ball’s motion and the horizontal velocity versus time graph (X velocity vs. t). For the velocity graph, right-click on the y-axis and select “Autoscale” → “Autoscale From 0”. This will scale the graph starting from a velocity of 0m/s.
5 Describe what happens to the horizontal part of the ball’s velocity during its motion ON the table (to the left of the dashed line)?
6 What is ball’s acceleration in the X direction while ON the table? ax = ______m/s/s
7 What does this suggest about the sum of the forces in the X direction while ON the table?
8 Describe what happens to the horizontal part of the ball’s velocity during its motion OFF the table (to the right of the dashed line)?
9 What is ball’s acceleration in the X direction while OFF the table? ax = _____m/s/s
10 What does this suggest about the sum of the forces in the X direction while OFF the table?
11 Record the vertical position versus time graph (Y vs. t) for the ball’s motion and the vertical velocity versus time graph (Y velocity vs. t). For the velocity graph, right-click on the y-axis and select “Autoscale” → “Autoscale From 0”. This will scale the graph starting from a velocity of 0m/s.
12 Describe what happens to the vertical part of the ball’s velocity during its motion ON the table (to the left of the dashed line on your graph above)?
13 What is ball’s acceleration in the Y direction while ON the table? ay = ______m/s/s
14 What does this suggest about the sum of the forces in the Y direction while ON the table?
15 Describe what happens to the vertical part of the ball’s velocity during its motion OFF the table (to the right of the dashed line on your graph above)?
16 What is ball’s acceleration in the Y direction while OFF the table? ay = _____m/s/s
17 What does this suggest about the sum of the forces in the Y direction while OFF the table?
Performing Video Analysis in Logger Pro
1 Open Logger Pro.
2 From the Command Bar, click on Insert and select Movie.
3 The movie viewer window(similar to the picture on the right) should appear on the screen. For the best results, make the movie viewer window as large as possible by clicking and dragging on the ‘handles’(the small black squares) on the perimeter of the window.
4 In the bottom right hand corner of the movie view window is the Enable/Disable video analysis button shown on the right. Click
on this button to begin video analysis.
5 After enabling video analysis, a tool bar will show up on the right hand side of the movie viewer window. An image of this tool bar is shown on the right:
6 Begin by selecting the Add point tool. ()
Pick a point on the moving object and mark its location in the frame by clicking on the point. Advance a few frames and repeat this process or marking and advancing until you get to the end of the movie.
7 Because Logger Pro measures position values in pixels on the computer screen, you will need to use the Set scale tool to tell the computer how many meters each pixel represents:
a Click on the Set scale tool: ()
b Click on one end of the meter stick and drag to the other end of the meter stick then release the mouse key.
8 Logger Pro assumes that the origin of the coordinate system is in the bottom left hand corner of the screen. If you need to change the location of the origin, you can select the Set origin tool: ()
and click on the location where you want the origin to be located.
At this point if you check the data table, you should have column for time, t, horizontal position, x, vertical position, y, horizontal velocity, vx, and vertical velocity, vy. The graph now should show plots of position vs. time.