C. Their strengths are added
Answer:
Relative density is a ratio of the density of a certain material to the density of a reference material. Relative density has no unit, because the units of the material in question cancel out with the units of the reference material. For example, say a cooking oil’s density is 0.9 g/cm^3.
Explanation:
If the mass of one object is doubled, the force between these objects will also double.
Force refers to an influence on a body which can change its state of rest or motion.
Force F = G(mM/d^2) (where m is the mass of first object, M is the mass of the second object and G is the gravitational pull and d is the distance between the two objects)
The force between two objects (m and M) (according to the universal law of gravitation) is proportional to their mass and reciprocally proportional to the square of their separation (R) between them.
So F' = G(2mM/d^2),
which means F'=2F
Therefore, the when the mass is doubled, the force also doubles.
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