Total distance = 10 km + 10 km = 20 km
1 km = 1000 m
20km x 1000 = 20,000 m
Total time = 20 min. + 30 min. = 50 minutes
Average speed = Distance / time
Average speed = 20,000/50 min
Average speed = 400 m/s
This could be Hubble's law, or something related to it. I think there's a possibly Doppler RED SHIFT in the optical spectra of stars etc as observed on the earth. It seems that they are accelerating away from the earth, and that the further away they are the faster they are moving.
It seems that this has been connected to the idea of "The Big Bang" theory of the origin of the universe which seems to have superceded Professor Sir Fred Hoye's Steady State theory of the universe.
There's some Special Relativity in this lot, too.
Answer:
8 x 10^-8 C on both the spheres.
Explanation:
Number of electrons added to A = 1 x 10^12
As the sphere A and B are identical to each other so the charge is shared equally.
Charge of one electron = 1.6 x 10^-19 C
Charge on A after wards
= number of electrons after wards x charge of one electron
qA = 0.5 x 10^12 x 1.6 x 10^-19 = 8 x 10^-8 C
Similarly, the charge on sphere B afterwards
= number of electrons after wards x charge of one electron
qB = 0.5 x 10^12 x 1.6 x 10^-19 = 8 x 10^-8 C
Answer:
0.4455 m
Explanation:
g = Acceleration due to gravity = 9.81 m/s²
Total mass is

Here the spring constant is not given so let us assume it as 
Here, the forces are balanced

The springs are compressed by 0.4455 m