PURPOSE:
To expose the student to new equipment and lab procedures. And to work with vectors.

INTRODUCTION:
In physics there is a time honored question (and modern demonstration) concerning a monkey and a rifle. If a monkey is sitting in a tree and a hunter aims a paint ball gun at the monkey and fires, causing the monkey to instantly drop from the tree at firing(from seeing the puff of the gun): will the bullet hit the monkey even if he is falling? The instructor then informs the class that the monkey will indeed be struck even at a great distance and with the fact that the monkey is headed for the ground. The bullet accelerates down the hunters barrel and exits at the muzzle. Once clear of the barrel, the bullet travels with a set velocity. If this took place in some strange land where there were no gravity, the bullet would travel down its aimed path and hit the monkey. But here on earth, the monkey starts to fall due to gravity at the set rate of 9.8 m/s². BUT, so does the bullet! So for every cm that the monkey falls, so does the bullet since mass has no effect on the pull of gravity. Every cm drop the monkey experiences so does the bullet, keeping on its deadly path to the monkey. If the hunter aimed with good accuracy, the monkey is doomed to be splattered by the paint bullet.

In this lab you will take aim at a monkey and fire. If you hit the monkey, data can be gathered that will allow you to calculate the initial velocity of the paint bullet.

PROCEDURE:

1) You can adjust the background shading by clicking on the "Special" button to the right and selecting "Background". Click on the "Special" button and select "Print Blank Report" to obtain a web page that can be printed and used as a lab report. (the program will not be interrupted)

2) Click and drag the wooden stock of the paint ball gun (up and down) until the laser sight stops at the monkeys body. You now have the monkey in your sights! Record the angle of the gun. Click on the trigger to fire.

3) There is a photo sensor at the end of the gun. When the paint ball passes, it sends a signal to a device securing the rope that the monkey is holding on to, to release. Notice that the initial position of the monkey is now in shadow form.

4) If you aimed well, you will hit the monkey somewhere in its downward path. The point of impact will also show a shadowed form of the monkey. You have two tape measures, one horizontal and one vertical. Measure and record the distance (in meters) that the monkey fell before being hit by the paint ball. Measure and record the distance from the center of the blue sensor, on the paint gun barrel, to the center of the monkeys body as it fell. It may help to use the vertical tape to line up this point.

5) Click on the "Reset" button to start over and play with the angle and observe the results.

6) Calculate the requested values asked for on the lab sheet and any given by your teacher. For help on these values click on the "Special" button and select "View Data & Hints". Select "File Report" to send a copy to be viewed by your teacher.