Question

Two objects exert a gravitational force on 8 N on one another. What would that force be if the mass of BOTH objects were doubled?

Answer 1

D: 32 N

Step-by-step explanation:

Doubling the mass of one of the objects would double the gravitational force, to 16 N. If you then double the second mass, the force will again double, this time to 32 N.

Answer 2

Based on Newton's law of universal gravitation, the equation for the gravitational force exerted by an object on another object is given by:
F = Gm1m2/(r^2)
where G is the universal gravitational constant, F is the gravitational force exerted, m1 is the mass of the first object, m2 is the mass of the second object, and r is the separation distance between the two objects.
If the mass of both objects were doubled, then we would have: m1' * m2' = (2m1) * (2m2) = 4m1m2. Assuming r stays constant (G is a constant so that won't change anyway), then this means that the new force will be 4 times greater, ie 8N * 4 = 32N of gravitational force.