Answer:
v = 83.1 % of speed of light
Explanation:
given,
T_e is the earth time = 2.7 s
T_s is the ship time = 1.5 s
we know,

where c is the speed of light
v is the speed of the rock star moving



squaring both side


v = 0.831 c
v = 83.1 % of speed of light
The magnitude of that other charge will be 9×10⁻⁵ C. The force on the charge is inverse of the distance.
<h3>What is Columb's law?</h3>
The force of attraction between two charges, according to Coulomb's law, is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
The magnitude of that other charge is found as;

Hence, the magnitude of that other charge will be 9×10⁻⁵ C.
To learn more about Columb's law, refer to the link;
brainly.com/question/1616890
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Answer:
<em>Force B</em>
Explanation:
<u>Friction Force
</u>
It's a force that appears when an object is tried to move on a rough surface. There are two cases: when the object is at rest, we have the friction static coefficient and when the object is already moving, we have the dynamic coefficient. The static coefficient is usually greater than the second because it's harder to overcome the friction when the object is at rest.
We are told that John pushes the bed to the left with enough force to overcome the force of friction. If the movement is intended to be to the left side, the friction force appears to the right, since it always opposes to the movement. Thus the force B is the one who represents the friction force in this situation