Measuring Waves
What are two ways to increase the energy of a wave?
Increase the amplitude or the frequency.
Which waves move perpendicular to the resting line?
Transverse waves
What color(s) does grass absorb?
All colors except green
What types of electromagnetic waves are in sunlight?
Sunlight has white light which is all the colors of the visible spectrum. It also has invisible waves like ultraviolet light and infrared (heat).
How do you increase the resolution of an image? Why?
You would add more pixels because a picture is made up of hundreds of pixels of a single color. If there are more pixels, then the picture looks less pixelated, the picture is clearer, and it has higher resolution.
What is the place where the wave crosses the resting line called?
A node
How does sound travel to your ear?
An object vibrates which moves the air. The vibrations travel through the air (the medium) in compression waves and hit the ear which vibrates the bones and hairs inside of it. Then, the body interprets those noises.
Can mechanical waves (such as sound) be reflected and absorbed by materials?
How does light travel to your eyes?
Light travels from a light source to an object. Sometimes, some of the light is absorbed into the object, but the light that is reflected, reflects off the object and hits your eyes. The brain interprets this.
In what waves are digital waves better than analog waves?
Digital waves have better resolution & sound fidelity (they don't lose signal).
Digital waves are less affected by sources of noise.
Digital waves can be stored, copied, and transmitted more reliably.
Digital waves use broadcasting frequencies more efficiently.
Digital waves produce more sound and video choices like interactive features and on-demand services.
What is sound volume measured in?
decibels (dB)
What happens when you increase the amplitude or frequency of a sound wave? What would happen if you decreased the wavelength?
An increase in amplitude would make the sound louder. An increase in frequency would make the sound higher in pitch. A decrease in wavelength would mean that the frequency would increase because they are inversely related. So, the pitch would be higher.
If a student looks through a red filter at a white piece of paper, what will they see? Explain.
The student will see a red piece of paper. They will see this because the light from the light source is white and when it reflects off the paper, it is still white because the paper reflects all colors. However, once the light is reflected off the paper, it goes through the filter before it reaches the student's eyes. The filter only reflects red light and absorbs all other colors. Therefore, all the other colors besides red are absorbed into the filter and the red light is reflected and continues through the filter to the student's eyes. The student only sees the red light because all the other light is absorbed, so that is why the student sees a red paper.
Draw a diagram of a simple wave. Label the crest/peak, trough, nodes, wavelength, resting line, and amplitude.
Check in the textbook to see if you were right. I could not find a specific page with a diagram of a wave, but I'm sure you could find enough information to be able to tell if you are right or not.
How does a laser work?
A laser needs to be a narrow, focused beam so it must be coherent, or in phase. To do that, a medium is needed to focus the light. In a ruby laser, that medium is corundum. Inside of the laser, a rod of corundum is rapped with a light source. This light source makes pulses of light and this excites the light. When the light waves "calm down," they all become red which means they all have the same wavelength, are in phase, and are coherent. Around all of this is a tube with mirrors at both ends. The light reflects back and forth which excites even more light. As the light reflects back and forth it all becomes coherent. Together, the light waves increase in amplitude which means it has higher energy. All of this coherent light exits at a small hole at the end of the tube.
Find the frequency (waves/sec) of a wave if it has 180 wave cycles per minute.
You need to find waves per sec, but you have waves per min. There are 60 seconds in one minute. So, you divide 180 by 60 to get 3 waves per second.
3 waves per second is the answer.
Can you hear a sound wave in space?
No, because space is a vacuum. Sound waves travel by vibrating a medium such as air. It has to move particles to travel. Since there is nothing to move through in space or any other vacuum, sound cannot travel.
What is the Law of Reflection? If the angle of incidence is 40 degrees, what is the angle of reflection?
The angle of incidence (the angle at which the original beam hits something reflective) is equal to the angle of reflection (the angle of the beam reflected). So, if the angle of incidence is 40 degrees, the angle of reflection is 40 degrees.
What does it mean to have coherent light waves?
Coherent light waves are light waves in phase. Light in phase means that all the waves are peaking and troughing at the same time. This creates a narrower, more focused beam.
How does information travel through optical fibers? What happens if the fiber is bent too far?
A computer only sees information as binary numbers. It can modulate (change/encode) this binary data (sequences of 0s and 1s) into a carrier wave with the same sequence. This carrier wave is in light form. A laser sends the light through optical fibers. When the light hits the sides of the fiber, all of it is reflected and no light is leaked. This is called total internal reflection. This way, all of the light information goes through an optical fiber over long distances and none of it is lost. However, if the fiber is bent too far, total internal reflection is lost and some of the light information is lost. When the light reaches its destination, a computer on the other end demodulates (decodes) the carrier wave and then the information is in binary form again, a language that the computer understands and can portray to humans. Sound waves, both digital and analog, can be transmitted this way. There are two main ways to modulate sound waves in the U.S. You can change the amplitude to show different binary sequences or you can change the frequency. When you change the amplitude, this is called amplitude modulation (AM). When you change the frequency to show different binary sequences, it is frequency modulation (FM). As you know, these are the different types of radio stations you can get in the U.S. The stations are AM or FM depending on how they modulate (encode) their audio data so that it can be transmitted to anyone listening on their radio.
Find the velocity of a wave if the node to node length is 10 centimeters and there are 60 waves per minute. Find the velocity in centimeters per second. Velocity=frequency*wavelength
If there are 60 waves per minute that means that there is 1 wave per second because there are 60 seconds in a minute and 60/60=1.
Therefore, the frequency= 1 wave/sec.
Next, find the wavelength. A wavelength is crest to crest, trough to trough, or node to node times two. Since the node to node measurement was given as 10 centimeters that means the wavelength is double that.
So, wavelength is 20 cm.
Then, you multiply the wavelength by the frequency.
1 wave/second*20 cm= 20 cm/sec.
To explain this, there is 1 wave cycle for every second passed. Each one of these waves is 20 centimeters long. So the wave is traveling 20 centimeters every time a wave cycle is completed. So, velocity, or speed, of the wave is 20 cm per 1 second (it travels 20 centimeters in one second).
What are analog waves and what are digital waves?
Analog waves are smooth and continuous waves that communicate data. A digital wave is wave that steps instead of flows continuously in a curve, but it also communicates data. A digital wave can look more like an analog wave if it has a higher sampling frequency. This means that it has more steps, so it looks like a curve.
Draw a diagram of a laser reflecting off a mirror. Use the terms normal line, angle of incidence, and angle of reflection.
Check your answer with the diagram on page 31 of the Waves textbook in FossWeb.
What is light made of? How does it travel?
Light is made of packets of light called photons. These photons are like particles, but they also move like waves (it's called wave-particle duality, but that's not in our textbook so you don't need to know that). It travels in waves of both electricity and magnetism (electromagnetic waves). Light travels in a straight line called a ray. It doesn't have to travel through a medium.
How do you design an engineering project?
First, you know the criteria and constraints. Criterion are the specifications/needs of the project (what the project is trying to accomplish). Constraints are barriers to completing some part of the project (budget, laws, etc.). Then, you need to design a model/solution for the project. Next, you test the project. Then, you improve the design by brainstorming changes and testing those by changing only one variable at a time. (All parts of this answer must be given for points to be received).