Pulse Speed
Pulse Speed
Definition: Pulse speed
Pulse speed is the distance a pulse travels per unit time.
Quantity: Pulse speed (\(v\)) Unit name: metre per second Unit symbol: \(\text{m·s$^{-1}$}\)
Speed is defined as the distance travelled per unit time (this will be covered in more detail in Motion in One Dimension). If the pulse travels a distance \(D\) in a time \(t\), then the pulse speed \(v\) is:
\[v = \frac{D}{t}\]
Example:
Question
A pulse covers a distance of \(\text{2}\) \(\text{m}\) in \(\text{4}\) \(\text{s}\) on a heavy rope. Calculate the pulse speed.
Step 1: Analyse the question
We are given:
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the distance travelled by the pulse: \(D = \text{2}\text{ m}\)
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the time taken to travel \(\text{2}\) \(\text{m}\): \(t = \text{4}\text{ s}\)
We are required to calculate the speed of the pulse.
Step 2: Apply the relevant principles
We can use:
\[v = \frac{D}{t}\]to calculate the speed of the pulse.
Step 3: Do the calculation
\begin{align*} v & = \frac{D}{t} \\ & = \frac{\text{2}\text{ m}}{\text{4}\text{ s}} \\ & = \text{0.5}\text{ m·s$^{-1}$} \end{align*}Step 4: Quote the final result
The pulse speed is \(\text{0.5}\) \(\text{m·s$^{-1}$}\).
Tip:
The pulse speed depends on the properties of the medium and not on the amplitude or pulse length of the pulse.
This lesson is part of:
Mechanical Waves and Sound