Describe the differences between mechanical wave and an electromagnetic wave.
Mechanical waves require a medium to travel through
Electromagnetic does not and can travel through empty space
Describe the different between a longitudinal and transverse wave.
Transverse waves are particles in the medium that vibrate perpendicular to the direction of the wave.
Longitudinal waves vibrate parallel to the direction of the wave.
When a wave passes into a new medium, what remains the same? What changes?
When a wave enters a new medium, its frequency stays the same, but its speed and wavelength change.
Frequency and period stay
Speed and wavelength change
What length of vertical mirror is needed for a person to see the full length of their body?
A person only needs a mirror that is half their height to see their whole body.
The light reflects at equal angles, so rays from the head and feet meet the eyes using just half their mirrors length.
Why can you see yourself when you look in a mirror but not when you look at a wall?
A mirror has a regular reflection where regular light back to your eyes, creating an image.
Diffuse reflection scatters light all directions and reflected rays are not parallel.
Explain wave interference
It’s the effect when 2 waves or more overlap, either adding together (constructive) or cancelling each other out (destructive)z
Using what you know about sound waves, explain why sound waves travel faster in a denser medium and slower in a less dense medium.
Sound waves travel faster in denser mediums because particles are closer together, so vibrations transfer more quickly from one particle to the next.
Explain diffraction
Bending of waves when they encounter a small encounter a small opening in a barrier slit.
Explain Polarization
Process of limiting the particle vibrations of a transverse wave to one dimension.
Filtering a transverse wave so that it’s particles can only vibrate in one perpendicular plane.
Radio waves are diffracted by large objects such as buildings while light is not noticably diffracted. Why?
The wavelength of light is much, much smaller than the wavelength of radio waves. The larger the wavelength the more bending or diffraction will occur, so radio waves with differact more due to the large wavelengths.
What is white light? How can you seperate white light into different colours?
White light is the mixture of all wavelengths of light in the visible spectrum. To separate white light to see individual colours, refract the light by sending it into a new, denser medium (like a solid transparent prism) that will cause wavelengths at different frequencies to bend differently and become visible.
_______ waves require a material medium for energy transfer.
Mechanical
A ________ wave causes the particles of the medium to vibrate in a direction perpedicular to the direction in which the wave is traveling.
Transverse
_____________ waves can travel even if there is no medium.
Electromagnetic
A wave is a disturbance of ______ traveling through a medium or through space.
energy
The time for one wave cycle is a _______.
Period
The _________ of a wave is the number of waver per ___ second.
Frequency
1
The __________ of a wave is the linear distance between any two corresponding points on consecutive waves. (ie. trough to trough)
Wavelength
The energy content of a mechanical wave is chracterized by its __________.
Frequency
The _______ of a mechanical wave depends on the medium.
Speed
When waves pass from one medium into another, their ________ remains unchanged.
Frequency
__________ is the direction change of waves at the boundary between different media.
Refraction
The __________ is a line perpendicular to a barrier at the point where an incident ray strikes the barrier.
Normal
What is the principle of superposition?
Waves share space, energy combine, amplitutdes add together
