8.8 miles. You divide 22.4 & 2.55.
Answer:

Explanation:
The strength of the electric field produced by a charge Q is given by

where
Q is the charge
r is the distance from the charge
k is the Coulomb's constant
In this problem, the electric field that can be detected by the fish is

and the fish can detect the electric field at a distance of

Substituting these numbers into the equation and solving for Q, we find the amount of charge needed:

Answer:
4800
Explanation:
You have to multiply the 1200 kg and the 2 m/s2. Then multiply the other 2 by the 2400 because it was the answer to the first part now after you multiply your answer is 4800.
Answer:
Given a tube of diameter d, = 3cm = 0.03m
Pressure Balance
Mercury pressure at the tube bottom Pₓ = Pa + ρgh
where
Pa = Atmospheric pressure = 101kpa
ρ = Density of mercury = 13,546kg/m3
g = acceleration due to gravity
h = height of the tube?
Given
Bottom pressure in excess of the atmospheric pressure = 48kPa = Pₓ - Pa
Therefore, 48kPa = ρgh
h = 48(kN/m2)/ρg
h = 48,000kgms⁻²m⁻²/(13546kgm⁻³ x 9.81ms⁻²)
h = 0.36m
the tube is 36cm tall