Gravity
Mass and Distance
Everything that has a mass has gravity. Even you and I. Gravity depends on 2 things: it depends on mass and distance.
Here's 2 saying to help you remember how they affect gravity:
More Mass = More Gravity
More Distance = Less Gravity
The more mass an object has the more gravity it will have. Jupiter is much bigger than Earth so it has more gravity than Earth does.
The more distance that separates 2 objects the less gravity is felt between the two. Jupiter has a lot of gravity but because it's so far away from Earth, we don't feel it. The moon, on the other hand, is close to Earth so it is pulled toward the Earth.
This distance concept also applies on Earth. Someone standing on Mt. Everest is farther away from the center of the earth than someone standing at sea level. The person on Everest has more distance which means less gravity from earth affecting him. He weighs less.
To calculate weight you take mass x gravity. Gravity on earth is about 9.8 m/s2. So what's the weight of a 30 kg dog?
30kg x 9.8 m/s2 = 294 Newtons or 294 N
Warning!! Don't be tricked during the test. Read carefully. Sometimes it will ask for MASS instead of weight. Mass is in kilograms and so you'd just repeat that number back to them. The mass of the above 30 kg dog is just 30 kg.
Here's 2 saying to help you remember how they affect gravity:
More Mass = More Gravity
More Distance = Less Gravity
The more mass an object has the more gravity it will have. Jupiter is much bigger than Earth so it has more gravity than Earth does.
The more distance that separates 2 objects the less gravity is felt between the two. Jupiter has a lot of gravity but because it's so far away from Earth, we don't feel it. The moon, on the other hand, is close to Earth so it is pulled toward the Earth.
This distance concept also applies on Earth. Someone standing on Mt. Everest is farther away from the center of the earth than someone standing at sea level. The person on Everest has more distance which means less gravity from earth affecting him. He weighs less.
To calculate weight you take mass x gravity. Gravity on earth is about 9.8 m/s2. So what's the weight of a 30 kg dog?
30kg x 9.8 m/s2 = 294 Newtons or 294 N
Warning!! Don't be tricked during the test. Read carefully. Sometimes it will ask for MASS instead of weight. Mass is in kilograms and so you'd just repeat that number back to them. The mass of the above 30 kg dog is just 30 kg.