Question

An object on the surface of the Earth weighs 180N. What is the gravitational force on the object at a distance of 3d from Earth's center?
I understand how to findthe gravitational force between two objects but i don't understand this question

Answer 1

I assume d is the distance of earth's surface from center. Now we know that gravitational force is inversely proportional to the square of distance between the objects.

When the object was at earths surface (i.e. at distance d from center of earth) force was 180N

when the distance is made 3d that is 3 times, force will become 1/9

Answer 2

@abhisar thank you so much!