Answer:
a.) The electric and magnetic fields are in phase with each other as they propagate through space.
Explanation:
Electromagnetic wave is a transverse wave in which magnetic field and electric field both induces each other as both changes with time
Here magnetic field induces electric field and similarly magnetic field induces electric field.
As we know that this is a transverse wave so here magnetic field and electric field lies in perpendicular planes. but they both propagate in same direction in such a wave that both fields reaches their maximum position and minimum positions simultaneously
So the correct answer is
a.) The electric and magnetic fields are in phase with each other as they propagate through space.
To solve this you must set up what is called a proportion. A proportion is a way of comparing two comparing values where one of the four values is missing. In your problem the missing value is the height of the smallest tree in the model.
To set up a proportion, you need all of your values. The easiest way to do this is to list them:
Highest tree in real life: 40ft
Highest tree in model: 10ft
Smallest tree in real life: 4ft
Smallest tree in model: x
So know you can set your proportion like this:
40/4 = 4/x
(When setting up a proportion, you always want to have the values belong to each other. For example don't put the height of the small tree in the model underneath the value of the highest tree in real life.)
So know to find what the x values equals, we need to cross multiply. And then all that's left after that is to solve for x.
40 times x = 4 times 4
40x = 16
x = 2.5
The smallest tree in the model should equal 2.5 feet.
Hope this helps! :)
Answer:
Acid mine drainage is dissolved toxic materials wash from mines into nearby lakes and streams.
Explanation:
Acid mine drainage is the flow of acidic water with pH typically between 2 and 4, and high concentrations of other dissolved toxic materials from mines into nearby lakes and streams. It mainly occurs during metal sulfide mining, when the metal sulfide ore such as pyrite (FeS2) is exposed to water and oxygen from air to produce soluble iron and sulfuric acid.
Microorganisms, especially acidophile bacteria like Acidithiobacillus ferrooxidans grow by pyrite oxidation, i.e., oxidizing the Fe²⁺ in pyrite to Fe³⁺, which again react with pyrite and water to produce sulfuric acid. Then the acidic water flows into nearby water sources and reduces the pH value of water in those sources. As a result, heavy metals such as copper, lead, mercury, etc in other mineral ores also get dissolved into the water. The action of acidophile bacteria also increases the rate and degree of acid-mine drainage process.
The acid mine drainage causes water pollution and adversely affect the aquatic plants and animals. It also results in the contamination of drinking water, corrosion of infrastructures such as bridges, etc.
Answer:
Velocity, v = 0.239 m/s
Explanation:
Given that,
The distance between two consecutive nodes of a standing wave is 20.9 cm = 0.209 m
The hand generating the pulses moves up and down through a complete cycle 2.57 times every 4.47 s.
For a standing wave, the distance between two consecutive nodes is equal to half of the wavelength.

Frequency is number of cycles per unit time.

Now we can find the velocity of the wave.
Velocity = frequency × wavelength
v = 0.574 × 0.418
v = 0.239 m/s
So, the velocity of the wave is 0.239 m/s.