Select the correct answer.

What is the frequency of a wave having a period equal to 18 seconds?

A. [tex]$6.6 \times 10^{-2}$[/tex] hertz
B. [tex]$5.5 \times 10^{-2}$[/tex] hertz
C. [tex][tex]$3.3 \times 10^{-2}$[/tex][/tex] hertz
D. [tex]$1.8 \times 10^{-2}$[/tex] hertz
E. [tex]$8.0 \times 10^{-3}$[/tex] hertz



Answer :

Sure, let's go through the detailed, step-by-step solution for finding the frequency of a wave given that its period is 18 seconds.

1. Understanding the relationship:
Frequency ([tex]\(f\)[/tex]) and period ([tex]\(T\)[/tex]) of a wave are related by the formula:
[tex]\[ f = \frac{1}{T} \][/tex]
where:
- [tex]\(f\)[/tex] is the frequency in hertz (Hz)
- [tex]\(T\)[/tex] is the period in seconds

2. Plug in the given period:
The given period [tex]\(T\)[/tex] is 18 seconds.

So we can find the frequency using:
[tex]\[ f = \frac{1}{18} \text{ Hz} \][/tex]

3. Calculate the frequency:
Performing the division:
[tex]\[ f = \frac{1}{18} \approx 0.05555555555555555 \text{ Hz} \][/tex]

4. Convert the frequency to scientific notation:
The numerical value 0.05555555555555555 can be expressed in scientific notation. We find the closest standard form:
[tex]\[ 0.05555555555555555 \approx 5.555555555555555 \times 10^{-2} \text{ Hz} \][/tex]

To match with the given answer choices, it’s rounded up to one decimal place in scientific notation:
[tex]\[ 5.6 \times 10^{-2} \text{ Hz} \][/tex]

5. Match the result with the given answer choices:
Comparing the calculated frequency [tex]\(0.05555555555555555\)[/tex] Hz, the answer that corresponds to it is [tex]\(5.5 \times 10^{-2} \text{ Hz}\)[/tex].

Thus, the correct answer is:

B. [tex]\(5.5 \times 10^{-2} \text{ hertz}\)[/tex]