Answer:
In a two particle system, the center of mass lies on the center of the line joining the two particles.
Answer:
They move outwards.
They don't intersect each other at any point.
They show the electric field.
Explanation:
The planets have (their) moons. So the answer would be planets.
The answer would be stay because the surface is flat so it will stay!
Answer:
We need about 8769 meters of wire to produce a 2.6 kilogauss magnetic field.
Explanation:
Recall the formula for the magnetic field produced by a solenoid of length L. N turns, and running a current I:

So, in our case, where B = 2.6 KG = 0.26 Tesla; I is 3 amperes, and L = 0.57 m, we can find what is the number of turns needed;

Therefore we need about 39312 turns of wire. Considering that each turn must have a length of
, where D is the diameter of the plastic cylindrical tube, then the total length of the wire must be:

We can round it to about 8769 meters.