1. Weight, Mass and Gravity
Mrs. Long
5th Grade
Calera Middle School

2. Weight
Weight is a measurement of the force on an object caused by gravity trying to pull the object down.
Mars has less gravity than Earth. So, if you were on Mars, you would weigh less because the force of gravity wouldn’t be as strong as it is here on Earth.

3. Weight Does this mean you would suddenly be thinner on Mars?
No, you would have the same amount of mass as you do on earth.
So, on Mars, your mass would be the same as it is here on Earth, but you would weigh less because Mars has less gravity than Earth.

4. Gravity Gravity is an attractive force.
This doesn’t mean it’s pretty. What “attractive” means is that an objects gravity pulls other objects toward it.
The Earth’s gravity naturally pulls us, and everything else, toward the center of the planet, which keeps us from drifting off into space.

5. Mass Mass is the amount of stuff contained inside an object.
It takes a lot of mass to make a lot of gravity. The Earth has a lot of mass, so it has a lot of gravity.
The moon’s gravity is about 1/6 the amount of the Earth’s, because the moon has less mass than the Earth.

6. Put it all together… So what does all of this have to do with weight?
Well, weight is the force on an object caused by gravity trying to pull the object down. A scale measures how much gravity your mass has.
A person with more mass has more gravity, and therefore weighs more.

7. Weight in Space
You’ve probably seen video footage of astronauts walking on the moon. They seem to float between each step.
Remember that the moon has about 1/6 the amount of gravity that the Earth has.
If you went to the moon, you would weigh less than you do on Earth.

8. Weight in Space
Does this mean you would suddenly be thinner on the moon?
Of course not!
Your mass would be the same – there is not less of you on the moon than there is of you on Earth.
But your weight is different because the moon’s gravity is different.

9. Activity
You are going to determine how much Justin Bieber would weigh on each planet!
Remember, his mass will not change on each planet! Only his weight will change!
WHY?