Question

Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and the separation of the balls, what will now be the magnitude of the attractive force on each one?
a) 16F
b) 8F
c) 4F
d) F
e)F/4

Answer 1

Answer:

After studying the law of gravitational attraction, students constructed a model to illustrate the relationship between gravitational attraction (F) and distance. If the distance between two objects of equal mass is increased by 2, then the gravitational attraction (F) is 1/4F or F/4. How would this model, situation A, change if the mass of the spheres is doubled?

A)  A

B)  B

C)  C

D)  D

If you came here from usa test prep it is:

Actually A

But for the question given right now is D.

Explanation:

Answer 2

Answer:

New force, F' = F

Explanation:

Given that, two small balls, A and B, attract each other gravitationally with a force of magnitude F. It is given by :

$F=G\dfrac{m_Am_B}{r^2}$

If we now double both masses and the separation of the balls, the new force is given by :

$F'=G\dfrac{2m_A\times 2m_B}{(2r)^2}$

F' = F

So, the new force remains the same as previous one. Hence, the correct option is (d) "F"