✔ 最佳答案
Q: what is the meaning of gravitational pull?
Gravitational pull is the force of gravity. Any mass produces a gravitational field (重力場) around it. Gravitational pull is the force of attraction experienced by an object when it is in the gravitational field produced by another object.
(a) Using Newton's Law of Gravitation
The force of attration between A and B
= (6.67x10^-11) x (100) x (400)/(2/100)^2 N = 6.67 x 10^-3 N
(b) By Newton's Third Law of motion (action-reaction law), the force acting on A is of the same magnitude to the force acting on B.
Hence, force on B = 6.67x10^-3 N, but in a direction opposite to that on A.