Answer:
(A)
Explanation:
We know , electric potential energy between two charge particles of charges "q" and "Q" respectively is given by kqQ/r where r is the distance between them.
Since the two charged particles are moving apart, the distance between them (r) increases and thus electrical potential energy decreases.
Answer:
A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West
Explanation:
A) For this exercise we must use the expression of Faraday's law for a moving body
fem = 
fem =
- d (B l y) / dt = - B lv
B = 
we calculate
B = - 7.9 10⁻⁴ /(0.73 20)
B = 5.4 10⁻⁵ T
B) to determine which side of the bar is positive, we must use the right hand rule
the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.
Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West
It takes the shape of the cup and it can be sucked through a straw
The power require to keep the car traveling is 6,666 W.
The power of the engine at the given efficiency is 3,999.6 W.
<h3>What is Instantaneous power?</h3>
This the product of force and velocity of the given object.
The power require to keep the car traveling is calculated as follows;
P = Fv

The power of the engine at the given efficiency is calculated as follows;

Learn more about efficiency here: brainly.com/question/15418098
The work of Brian mind interface is to learn that’s my guess lol