PURPOSE:
To expose the student to new equipment and lab procedures. And to calculate the spring constant and Potential Energy of an unknown spring.

INTRODUCTION:
Elastic potential energy (PE_e) is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched. According to Hooke's law, the force required to stretch the spring will be directly proportional to the amount of stretch. Since the force has the form

F = -k x

then the work done to stretch the spring a distance x is

PE_e = 1/2 k x²

During this lab you will determine the spring constant of a spring and the potential energy stored as the spring is stretched.

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A Hooke's Law apparatus is provided to measure the distance a spring will stretch under the addition of known masses.

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A set of known brass weights will be provided along with an unknown mass. The distance a spring will stretch under theses masses will be determined

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If you get into trouble and perform some procedure that causes the lab to fail(lab equipment will no longer operate), you can press the "Reset" button and the simulation will return to the starting position.

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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) Drag the scale mounted on the Hooke's Law apparatus until the pointer is indicating 0 cm. Pick up a brass weight and drop it on the hanging support on the apparatus. (looks like an inverted "T") The weight support will drop down due to the stretching of the spring and indicate its distance dropped. Record this distance in meters. The slots on the weights are provided to allow the weight to be hung from a central vertical support rod.

3) Repeat this same procedure, adding one weight at a time, until 8 weights have been added to the weight support. Record the distance traveled after each addition.

4) Remove all of the brass weights and place them on the table. The spring indicator should return to 0. Hang the unknown mass from the loop under the weight support. Record the distance traveled by the spring.

5) 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.