Sub-Topic 4.1 Oscillations - Lesson 1 on SHM

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Sub-Topic 4.1 Oscillations Lesson 1 - Introduction to Simple Harmonic Motion (SHM)

Introduction: Have you ever felt you were the slave of a clock? Clocks are mechanisims that

include a pendulum or balance wheel whose repeated patterns of movement define

equal time intervals, one after another. Such repeated movements are called

periodic motion. Periodic motion may occur when a particle or body is confined

to a limited region of space by the forces acting on it and does not have

sufficient energy to escape...

Definition:

Oscillation - a motion that repeats itself in a regular cycle, such as a sine wave or pendulum.

Click to see some oscillations

Learning Objective: To discover characteristic aspects of the simple harmonic motion of a mass oscillating on a spring.

NOTE TO THE STUDENT: You may choose to look at the reading material on Simple Harmonic Motion BEFORE or AFTER you undertake the exploration using the PhET sim.

Exploration: Mass Oscillating on a Vertical Spring

Use this PhET Masses & Springs simulation to design an investigation to see how different factors affect the duration of one oscillation (complete cycle of motion from one extreme position and back to that same position e.g. lowest point, up to highest point and back down to lowest point again).

Check the "Stopwatch" box to bring up this timing instrument & time for a suitable number (multiple) oscillations, then divide by that number to get the "period", T, for the motion.

Investigate these independent variables:

a) mass (m) of object hanging on the spring.

b) distance (x) spring is extended downwards prior to release.

c) spring softness (k) (*applies only to spring 3). Let the lowest setting ("soft") be "1" and the highest setting ("hard") be "11".

Graph your results in LoggerPro and describe the relationship between each independent variable and period (T).

Reading Activity. Physics of simple harmonic motion explained with interactives

(*Look at first TWO(2) pages only up to but not including "damping".)

Plenary: Print and complete this question on Oscillation of a Spring.