And..............I dont think you wrote the whole question
Answer:
1.12 N
Explanation:
Let the masses be m and M and distance be d . Force between them is .28 N .
Applying Newton's law of Gravitation
.28 = G x m M / d²
distance is halved , so distance becomes d /2
Force of attraction = G m M / ( d/2)²
= 4 Gm M / d²
= 4 x .28
= 1.12 N .
The greater the waves will be mass
Yes, it is already happening. About 270 million years ago the continents collided to form Pangea, and now, after the continents separated they continue to drift apart. Attached is a picture of what it may all look like when they recollide. Scientist are still not really sure.