Answer:
Different
Explanation:
The hollow one will expand even more making it have a larger volume then the solid one so they are different
That's Ampere's Law. ( C ).
The magnetic permeability is the proportionality constant.
Answer:
16.63min
Explanation:
The question is about the period of the comet in its orbit.
To find the period you can use one of the Kepler's law:

T: period
G: Cavendish constant = 6.67*10^-11 Nm^2 kg^2
r: average distance = 1UA = 1.5*10^11m
M: mass of the sun = 1.99*10^30 kg
By replacing you obtain:

the comet takes around 16.63min