Answer:
The separation between the charges was decreased by a factor of 0.2
Explanation:
The Coulomb's force between two charges is given by;

r₂ = 0.2r₁
Therefore, the separation between the charges was decreased by a factor of 0.2.
Ware them down, its like rubbing two pieces of chalk together.
Weight is equivalent to the product of the mass of an object and the strength of the gravitational field.
Using:
F = ma
a = 8.2 / 5
a = 1.64 N/kg
The gravitational field strength is equivalent to 1.64 N/kg.
Answer:
Explanation:
We know that,
Neptune is 4.5×10^9 km from the sun
And given that,
Earth is 1.5×10^8km from sun
Then,
Let P be the orbital period and
Let a be the semi-major axis
Using Keplers third law
Then, the relation between the orbital period and the semi major axis is
P² ∝ a³
Then,
P² = ka³
P²/a³ = k
So,
P(earth)²/a(earth)³ = P(neptune)² / a(neptune)³
Period of earth P(earth) =1year
Semi major axis of earth is
a(earth) = 1.5×10^8km
The semi major axis of Neptune is
a (Neptune) = 4.5×10^9km
So,
P(E)²/a(E)³ = P(N)² / a(N)³
1² / (1.5×10^8)³ = P(N)² / (4.5×10^9)³
Cross multiply
P(N)² = (4.5×10^9)³ / (1.5×10^8)³
P(N)² = 27000
P(N) =√27000
P(N) = 164.32years
The period of Neptune is 164.32years