Answer:
B ) 1.5 m/s
Explanation:
For the apparent frequency reflected by enemy submarine , the Doppler effect formula is
F = F₀ ( V + v) / (V - v)
F anf F₀ are real and apparent frequency , V and v are velocity of sound and velocity of enemy submarine respectively.
ΔF / F₀ = 
Put ΔF = 200; F₀ = 100000 and V = 1482
200 / 100000 = 
v = 1.5 m s⁻¹ .
In step 1, to increase the potential energy, the iron will move towards the electromagnet.
In step 2, to increase the potential energy, the iron will move towards the electromagnet.
<h3>Potential energy of a system of magnetic dipole</h3>
The potential energy of a system of dipole depends on the orientation of the dipole in the magnetic field.

where;
is the dipole moment- B is the magnetic field


Increase in the distance (r) reduces the potential energy. Thus, we can conclude the following;
- In step 1, to increase the potential energy, the iron will move towards the electromagnet.
- In step 2, when the iron is rotated 180, it will still maintain the original position, to increase the potential energy, the iron will move towards the electromagnet.
Learn more about potential energy in magnetic field here: brainly.com/question/14383738
Although the green light flashes first, you are moving away from it, so it illuminates you at the same moment as the red light.
A green laser is frequently used by amateur astronomers because its visible beam may be used to point out stars and galaxies because it penetrates the atmosphere so far. Red lasers are less adaptable than green lasers. Each wave or component of light in a laser has been precisely aligned to form a single, strong beam.
Green DPSS lasers are the most popular and first emerged on the market about 2000. (also called diode-pumped solid-state frequency-doubled, DPSSFD). Due to the rarity of laser diodes in this wavelength region, they are more complicated than regular red laser pointers.
Green lasers have been used in head-mounted displays and laser guides for defense and security purposes. Amateur astronomers can also direct and track stars using green laser guides.
To learn more about a green light. Please visit the below link.
brainly.com/question/4503557
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