Mass and weight

MASS AND WEIGHT
Physics Project
By: Salim DogaN ZENGIN
GRAVITATIONAL FORCE
Hang something from the end of a spring balance and you can measure the downward pull from the Earth. The pull is called a gravitational force.

No one knows what causes gravitational force. But several things are known about it: All masses attract each other. The greater the masses, the stronger the pull. The closer the masses, the stronger the pull.


GRAVITATIONAL FORCE
The pull between small masses is far too weak to measure – less than one millionth of a Newton between you and the person the next to you for example. But the Earth has a such a huge mass that the gravitational pull is strong enough to hold most things firmly on the ground.

WEIGHT
Weight is another name for the gravitational force from the earth.
As weight is a force, its unit is the Newton.
On the earth, each kilogram of matter weighs 10 newtons.
People often use the word ‘weight’ when they really mean ‘mass’. If something has mass 50 kg it has 500 N weighs.
Go to the Moon. Even better, go deep into space, for away from all planets.
MASS AND WEIGHT
As different planets have different masses and sizes, your weight would vary from one place in the Universe to another. Take the case of a person with a mass of 50 kg :
50 kg MASS WEIGHT
deep in space 50kg zero
near surface of the moon 50kg 80 N
near surface of Jupiter 50kg 2700 N
near a black hole 50kg 100 million
MASS AND WEIGHT
Traveling around space is not going to get rid of the kilograms. Weight may vary, but mass stays the same. On the Moon for example, the gravitational pull is much less than on Earth. But the amount of matter in something is just the same. And it is just as difficult to speed up or slow down.