The wave speed completely depends on the characteristics and properties of the medium . . . physical properties for mechanical waves, electrical properties for electromagnedtic waves.
So if you want to change the speed of a wave, you have to change the medium . . . shoot it through some different kind of stuff. <em>(B) </em>
Answer: To determine acceleration ,Micah also needs the Time of the total trip in seconds.
Explanation:
Acceleration can be defined as rate of change of velocity.

for calculating acceleration, initial and final velocity are required in meter per second and the total time of the trip in seconds. Then acceleration is measured in meter per second square.
Thus, Micah knows that a car had a change in velocity of 15 m/s.To determine acceleration ,Micah also needs the <u>Time</u> of the total trip in seconds.
Answer:
122.84 J
Explanation:
Since plate is square, area, A is given by 
The distance between plates, d, is given in the question as 2mm=0.002m
Charge on plate, Q, as given in the question is 240 
Assuming mica dielectric constant, k of 7
Capacitance, C is given by
C=
Stored energy, E is given by
E=
Therefore, the stored energy is 122.84 J
Every person is different. But for a planet-wide overall average that roughly represents all human beings on Earth, the figures usually used are:
from 20 Hz to 20,000 Hz .
Hydrogen has one proton whereas helium has two protons in its nucleus.
<h3>How hydrogen and helium atoms different from one another?</h3>
Atoms of hydrogen have a single proton in their nucleus and a single electron in the lowest energy level while on the other hand, Helium atoms have two protons in the nucleus and two electrons in the lowest energy level. In this way, we can say that the atomic number of hydrogen is 1 whereas the atomic number of helium is 2 because of the presence of two protons. Hydrogen atom has no neutron while on the other hand, the helium atom has one neutron in its nucleus.
So we can conclude that Hydrogen has one proton whereas helium has two protons in its nucleus.
Learn more about atom here: brainly.com/question/6258301
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