<span>They are used to measure and map effluent and pollution discharges from factories and sewerage plants, and the movement of sand around harbours, rivers and bays. Radioactive materials used for such purposes have short half-lives and decay to background levels within days.</span>
Answer:
The gazelles top speed is 27.3 m/s.
Explanation:
Given that,
Acceleration = 4.2 m/s²
Time = 6.5 s
Suppose we need to find the gazelles top speed
The speed is equal to the product of acceleration and time.
We need to calculate the gazelles top speed
Using formula of speed

Where, v = speed
a = acceleration
t = time
Put the value into the formula


Hence, The gazelles top speed is 27.3 m/s.
Answer:
The answer is B) Isla had a different time than hazel
Explanation:
Concept:
Frequency- It is defined as the number of oscillations occur in one second.
Its SI unit is Hertz (Hz)
Given: Produced sound vibrations is 18,500 cycles in 0.75 seconds
∵ In 0.75 second, produced sound has oscillations = 18,500 cycles
∴ In 1.0 second, produced sound has oscillations = (18,500 ÷ 0.75) Hz
The frequency of the sound will be ≈ 24,667 Hz
From the study of the given graph, only the animals (c) Cats, (b) Moths and (a) Bats can hear the produced sound because their upper audible frequency range is greater than 24,667 Hz.
The answer is true about the cabins in commercial airliners that require pressurization.
<h3>Why are the cabins of commercial airplanes pressurized?</h3>
Airplanes are pressurized because the air is very thin at the high altitude where they fly. The passenger jet has a cruising altitude of about 30,000 - 40,000 feet. At this altitude or height, humans can't breathe very well and our body gets less amount of oxygen. Most aircraft cabins are pressurized to an altitude about 8,000 feet. This is called cabin altitude. Aircraft pilots have access to the control's mode of a cabin pressure control system and if needed it can command the cabin to depressurize.
So we can conclude that cabins in commercial airliners require pressurization because of the greater pressure of the surrounding environment.
Learn more about pressure here: brainly.com/question/28012687
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