1. (75%) Practice force and energy problems by completing
WeBWorK set # 4.
2. (25%) In the software download area of the Physics 121
website, located at
http://teacher.pas.rochester.edu/phy121/Software/SoftwareIndex.htm,
you will find a movie that shows the launch of the
space shuttle. Use
LoggerPro to analyze this movie and answer the following questions:
a. What is the vertical acceleration of the space shuttle?
b. What is the force generated by the engines?
Use the following steps in this analysis:
a. Download
the movie clip from the Physics 121 website.
b. Start LoggerPro.
c. From the
“Insert” menu, select “Movie” to open the movie
you want to analyze.
d. At the bottom
right-hand side of the video window you see a button with red dots
with allows you to “Enable/Disable Video Analysis”. Enable
video analysis a set of tools will appear on the right-hand side of
the video window.
e. Select the
ruler button to set the scale. Use the “ruler” on the
right of the space shuttle to calibrate your screen. After selecting
the ruler button you move your mouse to one end of the “ruler” in
the video, click-and-hold your mouse button, move your mouse to the other
end of the “ruler,” and release the mouse button. A
window will emerge, asking you for the length the
“green line” you just drew on the screen.
f. Use
the “red-green dot button” to add a “point series” and
use the mouse to determine the position of one particular point on the
space shuttle. Each time you select a position in a frame, the
video will advance to the next frame.
g. After completing
your data entry you will see that the x and y positions
and velocities for all frames are listed in the data table. These
data can be exported by selecting “Export as …. Text” from
the file menu. The file created can be opened with Excel and you
can use Excel to plot for example the vertical velocity as function of
time and determine the acceleration.
Hand in a graph showing the velocity of the
shuttle as function of time and describe how you obtained the acceleration
of the shuttle and the force generated by its engines. The answer
to this questions needs to be dropped off in the Physics 121 homework
locker in B&L, across from B&L 106. Please make sure your
work is clearly labeled with your name.
Last updated on
Friday, February 15, 2008 16:53
