Answer:
1 N
Explanation:
From coulomb's law,
The force of attraction between two charges is inversely proportional to the square of the distance between the charges.
From the question,
Assuming the charges are the same in both case,
F ∝ /r²....................... Equation 1
Fr² = k
F'r'² = Fr²........................... Equation 2
Where F' = First Force, r'² = First distance, F = second force, r² = second distance.
make F the subject of the equation,
F = F'r'²/r².................... Equation 3
Given: F' = 4 N, r' = 3 m, r = 6 m
Substitute into equation 3
F = 4(3²)/6²
F = 36/36
F = 1 N
It's the rate that energy is used or supplied
Answer:
a galaxy observed at a distance of 5 billion light-years
I'd go for D here. It also fits in with the idea of thermal expansion - as something is heated up, molecules vibrate and maybe collide. they vibrate with bigger amplitudes, so taking up more space, so expanding. maybe
