MASS AND WEIGHT MASS AND WEIGHT Physics Project Physics Project By: Salim DogaN ZENGIN GRAVITATIONAL FORCE GRAVITATIONAL FORCE Hang something from the end of a spring Hang something from the end of a spring balance and you can measure the downward pull balance and you can measure the downward pull from the Earth. The pull is called a from the Earth. The pull is called a gravitational gravitational force. force. No one knows what causes gravitational No one knows what causes gravitational force. But several things are known about it: All force. But several things are known about it: All masses attract each other. The greater the masses attract each other. The greater the masses, the stronger the pull. The closer the masses, the stronger the pull. The closer the masses, the stronger the pull. masses, the stronger the pull. GRAVITATIONAL FORCE GRAVITATIONAL FORCE The pull between small masses is far too The pull between small masses is far too weak to measure – less than one millionth weak to measure – less than one millionth of a Newton between you and the person of a Newton between you and the person the next to you for example. But the Earth the next to you for example. But the Earth has a such a huge mass that the has a such a huge mass that the gravitational pull is strong enough to hold gravitational pull is strong enough to hold most things firmly on the ground. most things firmly on the ground. WEIGHT WEIGHT Weight is another name for the gravitational Weight is another name for the gravitational force from the earth. force from the earth. As weight is a force, its unit is the Newton. As weight is a force, its unit is the Newton. On the earth, each kilogram of matter weighs On the earth, each kilogram of matter weighs 10 newtons. 10 newtons. People often use the word ‘weight’ when People often use the word ‘weight’ when they really mean ‘mass’. If something has mass they really mean ‘mass’. If something has mass 50 kg it has 500 N weighs. 50 kg it has 500 N weighs. Go to the Moon. Even better, go deep into Go to the Moon. Even better, go deep into space, for away from all planets. space, for away from all planets. MASS AND WEIGHT MASS AND WEIGHT  As different planets have different masses and sizes, As different planets have different masses and sizes, your weight would vary from one place in the Universe to your weight would vary from one place in the Universe to another. Take the case of a person with a mass of 50 kg : another. Take the case of a person with a mass of 50 kg : 50 kg MASS WEIGHT 50 kg MASS WEIGHT deep in space 50kg zero deep in space 50kg zero near surface of the moon 50kg 80 N near surface of the moon 50kg 80 N near surface of Jupiter 50kg 2700 N near surface of Jupiter 50kg 2700 N near a black hole 50kg 100 million near a black hole 50kg 100 million MASS AND WEIGHT MASS AND WEIGHT Traveling around space is not going to Traveling around space is not going to get rid of the kilograms. Weight may vary, get rid of the kilograms. Weight may vary, but mass stays the same. On the Moon for but mass stays the same. On the Moon for example, the gravitational pull is much example, the gravitational pull is much less than on Earth. But the amount of less than on Earth. But the amount of matter in something is just the same. And matter in something is just the same. And it is just as difficult to speed up or slow it is just as difficult to speed up or slow down. down. . planets. MASS AND WEIGHT MASS AND WEIGHT  As different planets have different masses and sizes, As different planets have different masses and sizes, your weight. million MASS AND WEIGHT MASS AND WEIGHT Traveling around space is not going to Traveling around space is not going to get rid of the kilograms. Weight may