1. Energy is the capacity to apply a force over a distance.
4.1 Properties of Waves
A wave is a disturbance or movement that transfers energy through matter or space.
Examples of waves include: water waves, sound waves, and microwaves.
Energy is the capacity to apply a force over a distance.
A force is a push or a pull on an object.
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2. A crest is the highest point on a wave.
Features of a Wave
A crest is the highest point on a wave.
A trough is the lowest point on a wave.
The wavelength is the distance, in metres, for one complete cycle of the wave.
Crest to crest or trough to trough.
The amplitude is the height of a wave crest or depth of a trough, as measured from its rest position.
Identify each of the lettered parts of the wave.
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3. The matter that waves travel through is called a medium.
Two Types of Waves
The matter that waves travel through is called a medium.
Some waves such as light waves, can travel through space where there is no medium.
Two types of waves that travel through a medium are:
Transverse wave – matter in the medium moves perpendicular to direction of the wave.
Compression wave – matter in the medium moves parallel to direction of the wave.
Transverse wave
Compression wave
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4. Frequency is usually measured in hertz (Hz).
Frequency is the number of repetitive motions, or oscillations , that occur in a given time.
Frequency is usually measured in hertz (Hz).
When the frequency of a wave increases the wavelength decreases.
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5. Frequency can be calculated using the following equation:
Frequency Equation
Frequency can be calculated using the following equation:
frequency = cycles/seconds
Use the above equation to find the frequency for each of the following:
a) A hummingbird flaps its wings 120 times in seconds.
b) A DVD spins 35 times in 7 seconds.
Go to the next slide to view the answers
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6. Frequency can be calculated using the following equation:
Frequency Equation
Frequency can be calculated using the following equation:
frequency = cycles/seconds
Use the above equation to find the frequency for each of the following:
a) A hummingbird flaps its wings 120 times in seconds. (40 Hz)
b) A DVD spins 35 times in 7 seconds. (5 Hz)
Take the Section 4.1 Quiz
See page 138
(c) McGraw Hill Ryerson 2007