Would there be a difference in gravitational force attraction between one Kilogram of Copper and one kilogram of Magnesium ?
The only difference would be the density. A mass of 1Kg would have different volumes depending on the material.
Depends on what kind of differences you're looking for. Copper is 5 times denser than Magnesium. A Mg sphere would be 1.7 (the cube root of 5) times larger than a copper sphere of the same mass. You could get that much closer to the centre of mass of a copper sphere than the centre of a Mg sphere. So an ant, standing on the surface of the sphere would detect a gravitational pull significantly higher for copper than for Mg. But at a distance, no. A mass of any size can be treated as a point. One foot from the CoM of copper would be identical to one foot from the CoM of Magnesium.
Somehow I have the feeling gravity is related to density . In the past some study on gravity on the earth the impression was made the mountain say Everest had high gravity and by the Indian ocean was one of the loves gravity forces , practically it should be the other way .
Actually I thought it was as you say, viz. that the Himalayas have anomalously low gravity, due to the double thickness of less dense crust arising from the Indian plate going under the Asia plate and thus displacing the denser mantle rocks, which causes the mountains to rise, as they are still doing, towards isostatic equilibrium. But all this is saying is that when you are close to a massive object extended in space, local density variations within it will affect the strength of gravity locally. It is all still based on the principle that the amount of mass is solely what is responsible for gravitation.
Intuition can really get you into problems with physics. It seems like something heavier should fall faster than somehting lighter. This was so obvious that it was just accepted as fact for 2000 years. All someone needed to do wast to test the idea but it was not tested because everyone had the feeling that heavier stuff falls faster.
The important part in your link being, "Gravity anomalies are often due to unusual concentrations of mass in a region".
Gravity Anomaly Maps and The Geoid The Earth’s gravity field is depicted in two principal ways: gravity anomaly maps and maps of the Earth’s geoid. Gravity anomaly maps (see globe below) show how much the Earth’s actual gravity field differs from the gravity field of a uniform, featureless Earth surface. The anomalies highlight variations in the strength of the gravitational force over the surface of the Earth. Gravity anomalies are often due to unusual concentrations of mass in a region. For example, the presence of mountain ranges will usually cause the gravitational force to be more than it would be on a featureless planet — positive gravity anomaly. Conversely, the presence of ocean trenches or even the depression of the landmass that was caused by the presence of glaciers millennia ago can cause negative gravity anomalies. http://earthobservatory.nasa.gov/Features/GRACE/page3.php So which weighs more a kilo of gold or a kilo of iron ?
From what I recollect in space feathers and the hammer should float and not fall. so in vacuum they will fall at the same rate,
Except they were on the Moon which has no atmosphere and they fell at the same rate under the Moon's gravity. Please Register or Log in to view the hidden image!
I would say as an experiment the conclusion would be that atmospheric pressure makes the difference Gravity + atmosphere ===== difference in speed , on earth No gravity no atmosphere === same speed , Moon High vacuum =========== same speed Earth
If there was no air resistance, then parachutes wouldn't work. Unless wearing a parachute makes you physically lighter, in which case - why isn't every overweight person carrying one?
Hmmmm..... So at a kilometer above Earth ; a feather would fall at same time as ten tons of lead ? Not.
