P6: Quiz 2 – Answers
1)
a) The frequency of a wave is the number of full/ complete waves that pass through a certain point each second
b) Frequency is measured in hertz (Hz) [or kilohertz (KHz), megahertz (MHz) or gigahertz (GHz)]
2) v = f x λ, or wave speed = frequency x wavelength
Wave speed is measured in metres per second (m/s), frequency is measured in hertz (Hz) and wavelength is measured in metres (m)
3) 52 m/s
4) 60 m/s
5) 2.48 x 109 m/s
6) 23 Hz
7) 1.5 x 1023 Hz
8) 12 cm
9) 9.7 m
10)
a) The time period is the time that it takes for one full wave cycle of the wave
b) T = 1 ÷ f, or f = 1 ÷ T
T is the time period in seconds (s) and f is the frequency in hertz (Hz)
11) 0.04 seconds
12) 1.25 x 10-4 seconds
13) 200 Hz
14) 6.25 x 107 Hz
1)
a) Define frequency with respect to waves.
b) What is frequency measured in?
2) Write the equation that links wavelength, wave speed and frequency. Give the units for each of the variables.
3) A wave has a wavelength of 1.3 metres and a frequency of 40 hertz. Calculate the speed of the wave.
4) A sound wave has a frequency of 2 KHz and a wavelength of 0.03 m. Calculate the speed of the wave.
5) A wave has a wavelength of 620 metres and a frequency of 4 MHz. Calculate the speed of the wave. Give your answer in standard form.
6) A wave has a wave speed of 92 m/s and a wavelength of 4 m. Calculate the frequency of the wave.
7) A wave has a speed of 3 x 108 and a wavelength of 2 x 10-15. Calculate the frequency of the wave. Give your answer in hertz and in standard form.
8) A wave has a speed of 0.6 m/s and a frequency of 5 Hz. Calculate the wavelength. Give your answer in centimetres.
9) A radio wave has a speed of 300,000,000 m/s and a frequency of 31 MHz. Calculate the wavelength of the wave. Give your answer in metres and to 2 significant figures.
10)
a) What is meant by the time period of a wave?
b) Write the equation that links time period and frequency. Give the units for the variables.
11) Calculate the time period for a wave that has a frequency of 25 Hz.
12) Calculate the time period for a wave that has a frequency of 8 KHz. Give your answer in standard form.
13) Calculate the frequency of a wave that has a time period of 0.005 seconds. Give your answer in hertz.
14) Calculate the frequency of a wave that has a time period of 1.6 x 10-8. Give your answer in hertz and in standard form.