Answer:
The Richter scale measures the largest wiggle (amplitude) on the recording, but other magnitude scales measure different parts of the earthquake. The USGS currently reports earthquake magnitudes using the Moment Magnitude scale, though many other magnitudes are calculated for research and comparison purposes.
C would be the right answer edu
Answer: E = 
Explanation: The formulae for intensity of an electric field of a solid metal sphere relative to a point is given below
r
where
,
, r = 0.1m r = is the position vector of the charge.
it has been stated in the question that the charge is placed at the center thus it has no position vector.

Answer:
The force of the impact would be smaller
Explanation: Examples:
If the force is big then the time would be small (2500N of Force = 10 seconds)
If the force is small then the time would be big (250N of Force = 50 seconds)
Impulse/Collision -> [Ft] = [M (vf-vo)] <- Change in momentum