1) the sun (greek name Helios gives heliocentric)
2) A. Newton's laws of motion can prove this as well as Kepler's Laws
3) D. Inertia keeps it from falling onto the sun and gravity keeps it from going off in a straight line
4) moons. They orbit planets not suns directly
5) B (International Space Station gives a hint)
<span>heat transfer though convection</span>
Answer:
, Attractive
, Repulsive
Explanation:
= -20 μC
= 50 μC
r = Distance between the charges = 2.5 cm
k = Coulomb constant = 
Electrical force is given by

The magnitude of force each sphere will experience is 
Since the charges have opposite charges they will attract each other.
Now the charges are brought into contact with each other so the resultant charge will be


The magntude of the force the spheres experience will be 
The spheres have the same charge now so they will repel each other.