Makeup Laboratory MAKE 2 COPIES of COVER PAGE

Makeup Laboratory--MAKE 2 COPIES OF COVER PAGE

PHYSICS 22 LABORATORY

O6 TORSION OSCILLATOR

Spring 06

NAME:DATE:

Partner’s Name:

Laboratory Instructor:

Laboratory Section:

OBJECTIVES:

This experiment is the rotational analog to the mass on a spring linear oscillator which you studied in class as an example of simple harmonic motion.. For a spring, the force is given by Hooke’s Law:

where x is the amount the spring has been stretched. For rotational motion, we know that F, m  I and x θ. For the analog of the spring constant k, let’s use k  c, the spring constant of a flat spiral spring. Hence Hooke’s law for rotation is

For the linear mass on a spring oscillator, the period is given by

.

.

You showed in class that the analogous equation for a rotational or torsion oscillator was

Your task today is to determine c from Hooke’s law and from the period of your torsional oscillator.

:

Reading:

Introduction:

Apparatus:

Procedure:

Note the coiled end of the spring will slip into the slot on the small pulley. Wind the thread several turns on the pulley below the spring.

MAKE SURE THE AIR SUPPLY IS ON and the pressure is at least 6 psi.

Part 1: Determine c by hanging three different masses on the string. Explain how you did this. Explain how this is related to the method you used to determine k, the spring constant, in the mass on a spring experiment.

Part 2: Remove the string from the apparatus. Rotate the disk one half revolution from equilibrium and release. Time 10 oscillations. Calculate c using a calculated value for I or a value you measured in a previous lab.

Measurements:

Part 1:

Part 2:

Analysis:

Part 1:

Part 2:

Part 3: Calculate the per cent difference between your two measurements for c.

Conclusions:

QUESTIONS: 1. If there was a difference in your two measurements ofc, what do you think was the source of the difference?