Idea 4of 8Builds onA push or a pull
How much stuff
Take the book to the Moon. Is there less book?
Today you'll discover
- what stays the same when a thing changes planet
- what the pull on it is not
- the word, and the unit, for how much
Think firstThe same book, carried to the Moon
The book goes to the Moon. Is there less of it?
Decide first, then press Next. Watch what changes and what does not.
A box with a dot at its centre resting on a heavy line. After a prediction the box itself is picked out, then a single arrow pointing straight down from the centre appears as a separate thing. The amount of stuff is then named. The last step asks the mass of a bag of sugar floating in orbit.
See the whole ideathe big idea and the key word, in one place
The big idea
Mass is how much stuff, in kilograms, the same everywhere.
Compare themMass: the amount of matter, in kilograms, fixed. The pull on it: a force, an arrow, different on every world. The next card prices that pull.
Key words
- mass
- the amount of matter in an object, symbol m, measured in kilograms; it does not change with location
- kilogram
- the unit of mass, symbol kg; a litre of water has a mass of about one kilogram
About this modelArrows are forces, not motion: a box can move with no arrow pointing its way.
Arrows are forces, not motion: a box can move with no arrow pointing its way.
Ready to use it?
- Say what happens to a described object's mass when it changes location, and why.