To find work, you use the equation: W = Force X Distance X Cos (0 degrees)
Following the Law of Conservation of Energy, energy cannot be destroyed nor created.
So you would do 75 N x 10m x Cos (0 degrees)= 750 J
Answer:

Explanation:
Using Newton's second law, we calculate the magnitude of the electric force between the spheres:

The magnitude of the charge in both spheres is the same. So, we calculate the charge, using Coulomb's law:

The answer you are looking for is B, hope this helps.
Because field lines don’t all go in to the pole. The bottom half go outwards not inwards.
Answer:
A
Explanation:
the horizontal and vertical force acting on it consist a net force on the inclined direction (30degrees below the horizontal) you can tell by the length of the horizontal component (try to see the 30degree incline as horizontal, because that's the direction of the displacement). net work done on the system results in an increase in energy. i hope this can help :D, i'm also taking the ap physics 1 exam tommorow.