A group of 8 year old kids think that mass and weight are the same, how would u explain they r different?

Question

using words they would understand

Answer 1

I would tell them this...

Let's pretend you were way off in the middle of outerspace and playing a game of tug o war with your friend, and you are using a big thick rope with a lot of mass. Your friend pulling on the rope is like gravity pulling on an object. To pull the rope over towards you, you need to pull harder than your friend. To pick something up on Earth, you need to pull harder than gravity.

But lets say your friend let's go of the rope and a weaker friend wants to play tug of war. With this friend, you don't have to pull as hard, just like on the moon, you don't have to try as hard to pick something up because gravity is weaker and so the object weighs less.

Now let's say your friend let's go of the rope. Even though your friend isn't pulling on the rope anymore, since the rope is very massive, you still have to pull hard on it to make it move towards you. This is like an object when no gravity is pulling on it. Asking how much something weighs, is like asking how hard you have to pull on the rope when one of your friends is pulling on it. How much mass something has, is like asking how hard you have to pull on the rope when no one else is pulling on it.

So you might weigh less on the moon because gravity isn't pulling on you as hard, but you still have the same amount of mass as you did on Earth.

Answer 2

Ok think of it this way. Mass is really the fundamental atomic weight of something. That is to say that the electrons, protons and other particles all have a fundamental mass when compared to each other. Take these same particles to Jupiter and they will all compare to each other. However they will not weigh the same. Why? Because the gravity is greater there. On the moon they would way less but they would still have the same ratio of mass to each other. Mass is fundamental and weight depends on where you are. You will weigh slightly different in different places on the earth's surface because the earths gravity is not exactly the same in every place.

Answer 3

That's a trickey one because most adults don't seem to get the difference either.

If you want to measure the mass of something you could weight it - that works fine on earth - but what if you should happen to travel into space or sit inside a centrifuge. Not so easy then is it?

If you have different objects all the same size and shape you can tell which one is heavier by sliding them on a table. the more massive they are, the more force you need to start them and stop them. This works ok in space or in a centrifuge as well.

Answer 4

Weight depends on gravity. Mass does not. Your weight on the moon is different than your weight on the earth however your mass is the same.

Mass is the measure of the amount of material in an object.
weight is a measurement of the gravitational force acting on an object.

Answer 5

Use an 8 oz glass and an 8 oz paper cup of just about the same size. One, of course, will be lighter than the other even though they may be of the same size. Kids learn best through a "show and tell" method.

Answer 6

Fill two containers of equal size with matter of significantly different mass like flour and sand then:
1. have them attempt to move each one
2. if the containers are mobile, roll one into the other at rest and vise-versa to show the difference in reaction to the collision depending on which object was at rest before the collision
3. place each container on top of a malleable substance like clay and demonstrate the difference in depth of the impression made in the substance by the containers

Answer 7

Weight depends on gravity, mass is the amount of matter grouped together and does not depend on gravity. If you were in space with no gravitational bodies around, you would be weightless but not massless.

Answer 8

Have them hold a roll of coins and then hold a pillow...The roll of coins has more weight but less MASS...The pillow takes up more space but weighs less.