Wave Math (v = fλ)
A wave has a speed of 10 m/s and a wavelength of 2 m. Find the frequency.
Answer acceptable with or without significant figures
f = v / λ
f = 10 / 2
f= 5 Hz
Which type of wave does not require a medium to travel through?
A. Seismic waves C. Sound Waves
B. Ocean waves D. X- Rays
D. X- Rays
electromagnetic waves are:
radio, micro, infrared, visible, ultraviolet, x-ray, gamma
mechanical waves are:
seismic, sound, ocean, water
The highest point on a transverse wave is the ________.
crest
As frequency increases, wavelength ___________ (speed stays the same)
decreases
True or False: All EM waves travel at the same speed in a vacuum.
True - only the medium waves pass through change the speed
A wave has a frequency of 4 Hz and a wavelength of 3 m. What is the wave speed?
Answer acceptable with or without significant figures
v = fλ
v = (4)(3)
v =12 m/s OR w s/f = 10 m/s
Which of the following is not an example of a medium:
A. Air C. Oil
B. Water D. Energy
D. Energy
A medium is any solid, liquid or gas (matter!) Energy is not a form of matter.
The lowest point on a transverse wave is the ________.
trough
Increasing amplitude of a wave _________________ the energy.
increases
waves with greater distance from equilibrium to peak or trough have a larger amplitude and carry more energy
The part of the EM spectrum that humans can see is ______________.
Visible Light
A wave travels at 18 m/s with a frequency of 6 Hz. What is the wavelength?
Answer acceptable with our without significant figures.
λ= v / f
λ= 18 /6
λ= 3 m
True or False: Mechanical waves can travel through empty space?
False
Mechanical waves require a medium/matter
Electromagnetic Waves do not require a medium so they CAN travel through empty space
The distance from the equilibrium line to a crest or trough is the _______________.
amplitude
Two waves have the same speed. The wave with the shorter wavelength has the higher/lower frequency.
higher
True or False: If false correct the statement
A red object appears red because it absorbs red wavelengths of light.
reflects
A wave travels at 15 m/s and has a wavelength of 0.5 m. What is the frequency?
Include CORRECT significant figures
f = v / λ
f = 15 /0.5
f = 30 Hz
True or False:
Wavelength is the distance from crest to trough.
False
wavelength is the distance from crest to crest or trough to trough
The distance between two consecutive crests or troughs is the _______________.
wavelength
Two waves travel at the same speed. Wave A has a frequency of 8 Hz and Wave B has a frequency of 4 Hz. Which wave has a longer wavelength. DRAW THIS ON THE BOARD TO PROVE YOUR CHOICE.
Wave B
The sun is a source of what 3 types of electromagnetic waves?
infrared, visible, ultraviolet
A wave has a wavelength of 1.2 m and travels at 24 m/s. What is the frequency?
Include CORRECT significant figures
f = v / λ
f = 24 / 1.2
f= 2.0 x 101 Hz OR 20. Hz (need the decimal)
True or False: If false fix the statement.
Only electromagnetic waves carry energy.
All waves carry energy
Mechanical and electromagnetic waves carry energy
What are the units of speed, frequency and wavelength?
speed = m/s
frequency = Hz
wavelength = m
List all 7 electromagnetic waves in order of increasing energy. This means start with the lowest energy wave first.
2. Microwaves
3. Infrared 6. X - Ray
4. Visible 7. Gamma
Which color of visible light has the highest energy?
Violet
ROYGBIV
lower energy to higher energy