Physics Honors/AP 1 and 2

Spring Constants

# Lab: Spring Oscillation

#### Goal: To determine the spring constant for a 5" spring and observe oscillation dependence on amplitude and load.

Review the behavior of a spring using the My Physics Lab simulation. Adjust the initial position, damping, spring stiffness, and initial rest length.

#### Materials

• One or more 5" springs (available at a hardware store)
• Stand to allow you to hang spring vertically.
• Graph paper, ruler, or other device to measure position of spring.
• Masses to hang from spring
• Stopwatch or other timer

#### Procedure

1. Hang your spring and measure the lower end position when the spring is at rest.
2. Hang your initial mass from the spring and allow the spring to come to equilibrium. Measure the distance from the rest position of the empty spring to its new position. Determine the spring constant from Fspring = -kx.
3. Pull the spring down a few centimeters (recording new initial position), and release the spring. Time 10 oscillations and note the maximum extension of the final oscillation as closely as possible.
4. Describe the motion of the spring, noting its position when velocity is at maximum and minumum. Determine when acceleration is at maximum and minimum.
5. Predict the change in oscillation if you change the a) the mass or b) the initial extension. Repeat your experiment with several different extensions and several different masses to check your predictions.
6. If it is possible to observe amplitude for each oscillation (you may need to video tape the action and pull the readings from the video), record the amplitude.

#### Data Handling

1. Plot the change in period as a function of change in mass. Replot using the square of the period. Which plot produces a linear result?
2. Plot the change in period as a function of initial amplitude, then plot the square of the period as a function of initial amplitude.
3. What can you conclude about periodicity depency on mass and amplitude?

#### Report

1. Describe your materials, equipment, an dprocedures in sufficient detail that your fellow students could repeat your experiment.
2. Report your data as required above.