does the effect of gravity change on a moving object?

Question

let's say we drop a ball from a height of 1meter. Now, if we suppose that the force between the earth and the ball before dropping=9.8Newtons.According to the law of gravitation, the less the distance between 2 objects , the more the gravitational force between them. So after dropping the ball, the distance gradually decreases.So, wouldn't the force also increase?EXPLAIN????

Answer 1

Yes, the force increases as an object gets closer to the Earth's surface. Gravity is strongest at the surface of the Earth, even if an object is just one foot above the surface the force of gravity is less than at the surface. To determine the force of gravity on the moon by the earth's gravity you divide the distance to the moon, 240.000 Miles by the radius of the Earth, 4000 miles, it is 60. Multipy 60X60=3600, the pullof gravity on the moon is 3600 times weaker than it is at the surface of the Earth.

Answer 2

What you say is true. There's not much to explain except to say that over a 1 meter distance the effect is pretty small. It's the radius (from the center of the Earth), not the height above ground, that determines the change in gravitational acceleration. The ratio of the grav. accel. at 0 m height to that at 1 m is
(Rearth+1)^2/Rearth^2 or 6378161^2/6378160^2 = 1.0000003. So if the acceleration is 9.8 at 1m, it's 9.800003 at 0 m.