Happy Wednesday, 6th-grade scientists! In this Formative, you will read three passages about waves γ°οΈ and answer corresponding questions. This assessment will close by the end of this week, so make sure you complete it on time!
You can use your notes π !
How Do Satellites Work?
A satellite works by receiving radio signals π» sent from the Earth and resending the radio signalsπ» back down to the Earth. In a simple system, a signal is reflected, or "bounced," off the satelliteπ‘. For example, it is possible to bounce a signal off the surface of the Moonπ back down to Earth π. Because the Moon is very far away, for this to work the signal from the Earthπ must be very strong, and the receiver π‘receiving the signal must be sensitive enough to detect the very weak signal receive back from the moonπ.
Unlike a passive satellite such as the moon or the early ECHO satellite, a modern communications satellite receives the radio signal π‘ and sends it back down to Earthπ stronger than it was received. This process is called the "amplification" of the radio signal. In addition to amplifying the signal, a communications satellite also typically converts the radio from one frequency to another so that the signal getting sent down is not confused with the signal being sent up.
People communicate to a satellite using an antenna on the ground, which called an "earth station" in technical terms. The earth station sends up radio signals π‘ to the satellite. These signals are called "uplinks."
The satellite receives these signals, makes them stronger, and then re-transmits them back down to the Earthπ. These signals back to the Earth are called "downlinks."
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Question 1
1.
Which type of waves are radio waves?
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Question 2
2.
When the radio station makes the signals stronger (more energy), they need to increase the __________ of the wave.
Hint: look at this picture!
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Question 3
3.
What does the communication system do to avoid confusing the signals being sent to the satellite with the signals sent back to Earth?
Hint: the answer is in the second paragraph
How do dolphins use echolocation?
Dolphins are one of the few animals that can use sound to find their way around. This is called echolocation. Echolocation allows dolphins to βsee" by interpreting the echoes of sound waves π that bounce off of objects near them in the water π.
To echolocate objects nearby, dolphins produce high-frequency clicks. These clicks create sound wavesπ that travel quickly through the waterπ around them. In fact, sound waves travel almost five times faster through water than they do through air.
When the sound waves bounce off of objects, they return to the dolphins as echoes. Dolphins pick up those echoes with their lower jaw and their enormous foreheads. These areas have cavities filled with fatty tissues that channel the sounds toward the ears and then on to the brain, where they're interpreted.
So exactly what can dolphins βsee" via these echoes? A lot! Using a combination of regular sight and echolocation, dolphins are able to determine the shape, speed, distance, size, the direction of travel, and even some basic facts about the internal structure of objects in the water around them. This information is critical for dolphins to find food and navigate in dark or murky waters.
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Question 4
4.
Which wave behavior is involved in echolocation?
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Question 5
5.
Which body system does the brain belong to?
How did Bruce Banner become the Incredible Hulk?
If you're a marvel fan, you will be familiar with the green Giant -- Hulk! Gamma rays are blamed for making Bruce Banner the Incredible Hulk. But what are gamma rays and what can they really do?
Gamma rays are the highest-energy form of light. The rainbow πof visible light that we are most familiar with is just part of a far broader spectrum of light, the electromagnetic spectrum. Past the red end of the rainbowπ, where wavelengths get longer, are infrared rays, microwaves, and radio waves, while beyond violet lie the shorter wavelengths of ultraviolet rays, X-rays, and, finally, gamma rays.
A gamma-ray packs at least 10,000 times more energy than a visible light ray. Unlike the Incredible Hulk, gamma rays are not green. Scientifically speaking, how Bruce Banner survives his transformation is unclear. However, we know for sure that it can quickly destroy animal cells. Just as high doses of X-rays are typically lethal (can cause death), so too would an explosion of gamma rays kill the average person.
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Question 6
6.
Which type of wave are Gamma rays?
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Question 7
7.
Compared to visible light rays, Gamma rays have a _________ frequency.
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Question 8
8.
Compared to visible light rays, Gamma rays have ___________ energy.
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Question 9
9.
Matching phenomenon with the right term!
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Transmission of light waves
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Transmission of sound waves
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Absorption of light waves
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Reflection of light waves
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Reflection of sound waves
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Absoption of sound waves
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Question 10
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Great job, scientists! Not only have you learned about waves ππ§πΊππ²π‘π¦π, now you also know a little bit more about satellites π‘, dolphins and the incredible Hulk! Please comment below for any questions you still have and I will address them during next week's class!