Studying a Simple Harmonic Oscillator

Studying a Simple Harmonic Oscillator

Objective

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The simple harmonic motion of a pendulum can be studied by attaching a

ticker-tape to a pendulum bob and analyzing the dots marked on the

tape.

Theory

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In this experiment, a string was used to suspend a 0.5 kg mass.

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Refer to the diagram above,

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Considering the tangential force on the mass,

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∴The oscillation is simple harmonic.

Therefore, we can find out more on simple harmonic motion by analyzing

the ticker-tape we obtained after the experiment.

Apparatus

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1. 0.5 kg ringed mass

2. 1.5 m length of string

3. Ticker-tape timer

4. Ticker-tape

5. Low voltage power supply (a.c.)

6. Retort stand and clamp

Procedure

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1. The apparatus as shown in the figure was set up. A pendulum was

suspend by a string and was attached to a retort stand and clamp. A

ticker- tape was attached to the mass and was inserted to the

ticker-tape timer. The mass was pulled to one side. The timer was

switched on and the mass was allowed to swing to the other side.

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2. After the pendulum reached its highest position, the ticker-tape

timer was switched off and the ticker-tape was detached from the mass.

The dots marked on the tape were examined. During the oscillation, the

pendulum bob accelerated and then decelerated when it was approaching

its highest position. The acceleration of the bob was always pointing

towards its equilibrium position.

3. The two most widely spaced dots were marked on the tape - the zero

position of the pendulum bob was found.

4. Every dot on the tape was marked from the zero position. The

displacements of these points from the zero position were measured and

the corresponding time was worked out. Time interval between two

successive dots = 0.02 s.

5.