Physics 105

February 5, 2003

Today we will conclude our first exploration of velocity. The two techniques we have used so far in this course are:

1. Measure the difference in position at fixed time intervals (motion sensor)
2. Measure the difference in time at fixed distance intervals (photo gates)

The motion sensor measured the position of an object at different times, and uses this information to calculate the velocity and acceleration of the object. Another way to measure the position of an object at various times is to carry out a video analysis of the motion of this object. A video camera will record an image several times each second. Since the frame rate is constant, we can analyze the position of the object on each frame in order to obtain the time-dependence of the position of this object. Today we will use the video analysis tool in order to analyze the motion of two different objects (the space shuttle and the lunar module):

• Open the Space_shuttle.vpt file in your handout folder. Determine how the velocity of the space shuttle changes as function of time.
• Open the Lunar_Module.vpt file in your handout folder. Determine how the velocity of the lunar module changes as function of time.
• What are the errors in the measurements of the velocity and the acceleration?
• Compare the two different types of motion. What are their similarities and what are their differences ? Can you explain the differences?

Note: there will be no lab report due next week since I like to be able to return report # 1 and give you feedback on your style before asking you to write the next report.

© Frank L. H. Wolfs, University of Rochester, Rochester, NY 14627, USA

Last updated on Monday, February 3, 2003 10:42