Computer Intensive Physics
Day 7

Physics 211

Spring, 1998
February 3, 1998

Investigation of the motion of two objects traveling through the air.

Digital Video
Activity:Taking Data Using VideoPoint and a Computer
Movie: Vertical and Horizontal Motion from a Physics: Cinema Classics
videodisc.

You have access to a movie called Vertical and Horizontal Motion. Some of this movie was
digitized from a movie which was filmed at a rate of 24 pictures/second. Clip 3 was filmed for
slow motion. It shows two balls being released from a height of 1.66 meters.

Open the VideoPointsoftware, look in the Movies and Graphics Folder. Look at Frame 1,
Frame 2, Clip 1, Clip 2 and Clip 3.

1)Describe in words the physical systems shown in the three clips. Explain what happens.

Then use your knowledge of falling objects to compute the slow motion filming speed.

2)Slow motion picture rate =
so time between pictures =

pictures/second,
seconds. Explain your work.

Choose to record the data for TWO objects in several frames from Clip 3.

You may set the frame rate correctly and scale the image properly, using the options available from
the VideoPoint menu bar.

Collect two data points on each frame until the balls bounce off of the floor. Note that VideoPoint
can be set to advance automatically to the next frame afteryou have collected the second data
point on a frame. Note:You need an adequate number of data points, 20 to 30 say, and there
are about 500 slow motion frames - skip about 0.05 seconds between data points.

Export your data into Excel for analysis.

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