Physics Flashcards: Relate Wavelength Frequency Wave Speed

What this deck covers

This deck focuses on Relate Wavelength Frequency Wave Speed, giving you a quick way to review the definitions, rules, and examples that matter most for Physics.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What happens to wavelength $\lambda$ if $v$ is constant and frequency $f$ doubles?

Answer: $\lambda$ halves. Since $\lambda=\frac{v}{f}$, doubling $f$ halves $\lambda$.

Flashcard 2: Calculate $\lambda$ if $v = 20\,\text{m}\,\text{s}^{-1}$ and $f = 4\,\text{Hz}$.

Answer: $\lambda = 5\,\text{m}$. Apply $\lambda = \frac{v}{f} = \frac{20}{4} = 5$.

Flashcard 3: Calculate $f$ if $v=3\,\text{m}\,\text{s}^{-1}$ and $\lambda=0.25\,\text{m}$.

Answer: $f=12\,\text{Hz}$. Using $f=\frac{v}{\lambda}$: $f=\frac{3}{0.25}=12\,\text{Hz}$.

Flashcard 4: Identify the SI unit of frequency $f$.

Answer: hertz $(\text{Hz})$. Frequency measures cycles per second.

Flashcard 5: Calculate $v$ if $f=0.5\,\text{Hz}$ and $\lambda=8\,\text{m}$.

Answer: $v=4\,\text{m}\,\text{s}^{-1}$. Using $v=f\lambda$: $v=0.5\times^8=4\,\text{m}\,\text{s}^{-1}$.

Flashcard 6: Identify the proportionality between $f$ and $\lambda$ when $v$ is constant.

Answer: $f \propto \frac{1}{\lambda}$. Inverse proportionality when $v$ is constant.

Flashcard 7: Calculate $\lambda$ if $v = 1.5\,\text{m}\,\text{s}^{-1}$ and $f = 6\,\text{Hz}$.

Answer: $\lambda = 0.25\,\text{m}$. Apply $\lambda = \frac{v}{f} = \frac{1.5}{6} = 0.25$.

Flashcard 8: Calculate $f$ if $v=12\,\text{m}\,\text{s}^{-1}$ and $\lambda=3\,\text{m}$.

Answer: $f=4\,\text{Hz}$. Using $f=\frac{v}{\lambda}$: $f=\frac{12}{3}=4\,\text{Hz}$.

Flashcard 9: Identify the SI unit for wavelength $\lambda$.

Answer: $\text{m}$. Wavelength is a distance measurement.

Flashcard 10: Identify the SI unit of wave speed $v$.

Answer: $\text{m}\,\text{s}^{-1}$. Meters per second for velocity.

Flashcard 11: Find $\lambda$ if $f = 25\,\text{Hz}$ and $v = 5\,\text{m}\,\text{s}^{-1}$.

Answer: $\lambda = 0.20\,\text{m}$. Apply $\lambda = \frac{v}{f} = \frac{5}{25} = 0.20$.

Flashcard 12: What happens to frequency $f$ if wave speed $v$ is constant and wavelength $\lambda$ triples?

Answer: $f$ becomes $\frac{1}{3}$ as large. Since $v = f\lambda$ is constant, tripling $\lambda$ divides $f$ by 3.

Flashcard 13: What happens to wavelength $\lambda$ if wave speed $v$ is constant and frequency $f$ doubles?

Answer: $\lambda$ halves. Since $v = f\lambda$ is constant, doubling $f$ halves $\lambda$.

Flashcard 14: What is the rearranged formula for wavelength $\lambda$ in terms of $v$ and $f$?

Answer: $\lambda = \frac{v}{f}$. Rearrange $v = f\lambda$ by dividing both sides by $f$.

Flashcard 15: Identify the SI unit of wavelength $\lambda$.

Answer: meter $(\text{m})$. Wavelength measures distance between wave peaks.

Flashcard 16: Find and correct the formula error: $v=\frac{f}{\lambda}$.

Answer: Correct: $v=f\lambda$. The formula incorrectly divides; it should multiply $f$ and $\lambda$.

Flashcard 17: Find and correct the formula error: $\lambda=\frac{f}{v}$.

Answer: Correct: $\lambda=\frac{v}{f}$. The formula has $f$ and $v$ swapped in the fraction.

Flashcard 18: Identify the SI unit for wave speed $v$.

Answer: $\text{m}\,\text{s}^{-1}$. Meters per second is the standard unit for speed.

Flashcard 19: What happens to frequency $f$ if $v$ is constant and wavelength $\lambda$ triples?

Answer: $f$ becomes $\frac{1}{3}$ as large. Since $f=\frac{v}{\lambda}$, tripling $\lambda$ divides $f$ by 3.

Flashcard 20: Calculate $v$ if $f=5\,\text{Hz}$ and $\lambda=2\,\text{m}$.

Answer: $v=10\,\text{m}\,\text{s}^{-1}$. Using $v=f\lambda$: $v=5\times^2=10\,\text{m}\,\text{s}^{-1}$.

Flashcard 21: Find and correct the formula error: $v = \frac{\lambda}{f}$.

Answer: Correct: $v = f\lambda$. The given formula incorrectly divides; multiply instead.

Flashcard 22: Calculate $v$ if $f = 0.5\,\text{Hz}$ and $\lambda = 8\,\text{m}$.

Answer: $v = 4\,\text{m}\,\text{s}^{-1}$. Apply $v = f\lambda = 0.5 \times 8 = 4$.

Flashcard 23: Identify the SI unit for frequency $f$.

Answer: $\text{Hz}$. Hertz means cycles per second.

Flashcard 24: Find $f$ if $\lambda = 0.80\,\text{m}$ and $v = 16\,\text{m}\,\text{s}^{-1}$.

Answer: $f = 20\,\text{Hz}$. Apply $f = \frac{v}{\lambda} = \frac{16}{0.80} = 20$.

Flashcard 25: State the formula that relates wave speed $v$, frequency $f$, and wavelength $\lambda$.

Answer: $v = f\lambda$. Wave speed equals frequency times wavelength.

Flashcard 26: Calculate $\lambda$ if $v=20\,\text{m}\,\text{s}^{-1}$ and $f=4\,\text{Hz}$.

Answer: $\lambda=5\,\text{m}$. Using $\lambda=\frac{v}{f}$: $\lambda=\frac{20}{4}=5\,\text{m}$.

Flashcard 27: Calculate $\lambda$ if $v=1.5\,\text{m}\,\text{s}^{-1}$ and $f=6\,\text{Hz}$.

Answer: $\lambda=0.25\,\text{m}$. Using $\lambda=\frac{v}{f}$: $\lambda=\frac{1.5}{6}=0.25\,\text{m}$.

Flashcard 28: Find $v$ if $f=250\,\text{Hz}$ and $\lambda=0.40\,\text{m}$.

Answer: $v=100\,\text{m}\,\text{s}^{-1}$. Using $v=f\lambda$: $v=250\times^0.40=100\,\text{m}\,\text{s}^{-1}$.

Flashcard 29: Find $f$ if $v=60\,\text{m}\,\text{s}^{-1}$ and $\lambda=1.5\,\text{m}$.

Answer: $f=40\,\text{Hz}$. Using $f=\frac{v}{\lambda}$: $f=\frac{60}{1.5}=40\,\text{Hz}$.

Flashcard 30: What happens to wave speed $v$ if frequency $f$ doubles and wavelength $\lambda$ halves?

Answer: $v$ stays the same. Product $f\lambda$ remains constant: $2f \times \frac{\lambda}{2} = f\lambda$.

Flashcard 31: What happens to wave speed $v$ if $f$ doubles while $\lambda$ stays constant?

Answer: $v$ doubles. Since $v=f\lambda$, doubling $f$ doubles $v$ when $\lambda$ is constant.

Flashcard 32: What is the rearranged formula for frequency $f$ in terms of $v$ and $\lambda$?

Answer: $f = \frac{v}{\lambda}$. Rearrange $v = f\lambda$ by dividing both sides by $\lambda$.

Flashcard 33: Find $v$ if $\lambda = 0.40\,\text{m}$ and $f = 50\,\text{Hz}$.

Answer: $v = 20\,\text{m}\,\text{s}^{-1}$. Apply $v = f\lambda = 50 \times 0.40 = 20$.

Flashcard 34: Calculate $v$ if $f = 5\,\text{Hz}$ and $\lambda = 2\,\text{m}$.

Answer: $v = 10\,\text{m}\,\text{s}^{-1}$. Apply $v = f\lambda = 5 \times 2 = 10$.

Flashcard 35: Calculate $f$ if $v = 3\,\text{m}\,\text{s}^{-1}$ and $\lambda = 0.25\,\text{m}$.

Answer: $f = 12\,\text{Hz}$. Apply $f = \frac{v}{\lambda} = \frac{3}{0.25} = 12$.

Flashcard 36: Find $\lambda$ if $v=340\,\text{m}\,\text{s}^{-1}$ and $f=170\,\text{Hz}$.

Answer: $\lambda=2\,\text{m}$. Using $\lambda=\frac{v}{f}$: $\lambda=\frac{340}{170}=2\,\text{m}$.

Flashcard 37: Calculate $f$ if $v = 12\,\text{m}\,\text{s}^{-1}$ and $\lambda = 3\,\text{m}$.

Answer: $f = 4\,\text{Hz}$. Apply $f = \frac{v}{\lambda} = \frac{12}{3} = 4$.