Mass and Weight.

digme

I was just reading about mass and weight and found out that the weight of an object increases by 0.5% when you go from the equator to the north pole.
What would it take to be able to change gravity,besides mass of course.

Kevster

If you move faster, then gravity will have less affect on you too (i.e. - it'll have less 'pulling' power). I think that an electromagnetic field would affect it too...?

Edit: You should read about GOCE dude: http://www.esa.int/esaLP/SEMNBNKIWZF_LPgoce_0.html

"It is often assumed that gravity exerts an equal force everywhere on Earth. However, owing to factors such as the rotation of the planet, the effects of mountains and ocean trenches, and density variations in Earth’s interior, this fundamental force is not quite the same all over"

Colpriz

digme wrote: »

I was just reading about mass and weight and found out that the weight of an object increases by 0.5% when you go from the equator to the north pole.

What would it take to be able to change gravity,besides mass of course.

our position in the universe

Professor_Fink

Kevster wrote: »

If you move faster, then gravity will have less affect on you too (i.e. - it'll have less 'pulling' power).

Wait, what?

Kevster

The kinetic energy an object has when it moves reduces gravity's force, right? If I throw a ball horizontally, it wouldn't just fall straight down as it would if I had just dropped it. gravity gradually pulls it down instead as the ball's kinetic energy is reduced due to friction with the atmosphere.

It HAS been a long time since I did Physics... ...and I never even did it in the leaving cert.

Kevin

Podge_irl

Kevster wrote: »

The kinetic energy an object has when it moves reduces gravity's force, right? If I throw a ball horizontally, it wouldn't just fall straight down as it would if I had just dropped it.

It's movement in the radial direction would be exactly the same, i.e. it will fall at exactly the same acceleration, it will just happen to be moving sideways while falling. Kinetic energy does nothing to affect gravitational force (bar relativistic corrections, but I'm assuming they're not at play here).

Kevster

Okay, I can picture that - Thanks dude. My academic route from 5th year right through to now (research/PhD level) has been Biology, with a computer science detour :P

I was going to mention this earlier but was scared to: If I created a strong electromagnetic field by, for example, creating a cauldron of several tonnes of molten iron, that would affect the effects of gravity on objects nearby, right?

Kevin

Podge_irl

Kevster wrote: »

I was going to mention this earlier but was scared to: If I created a strong electromagnetic field by, for example, creating a cauldron of several tonnes of molten iron, that would affect the effects of gravity on objects nearby, right?

No. You need to understand the difference between an opposing force to gravity and something directly affecting the gravitational force. When you sit on a chair or stand on the ground, its an electromagnetic force that stops you "falling through the ground" and accelerating towards the centre of the earth. Similarly, you can see floating magnets and this kind of lark - none of these phenomena are in any way affecting the gravitational force acting on objects, but the EM forces are simply larger and acting to oppose gravity.

Vergast

Well put podge, confusing anti-gravity and opposing forces can lead to a lot of strange claims!