Answer:
F' = F
Explanation:
The gravitational force of attraction between two objects can be given by Newton's Gravitational Law as follows:

where,
F = Force of attraction
G = Universal gravitational costant
m₁ = mass of first object
m₂ = mass of second object
r = distance between objects
Now, if the masses and the distance between them is doubled:

<u>F' = F</u>
-- Multiply each side of the formula by 2
-- Then divide each side by t
-- Then subtract V(i) from each side.
Answer:
Friction always acts opposite to the motion.