Idea 1of 6Builds onThe net arrow
The ability to make change
What does a lifted crate hold that a resting one doesn't?
Today you'll discover
- what a winch gives a crate by lifting it
- why a still thing can hold the power to move
- the one word for what every store holds
Think firstA winch lifts a crate and holds it high
The crate hangs high and still. What did it gain on the way up?
Decide first, then press Next. Watch the hollow bar and the first bar fill.
An energy ledger: a small drawing of a winch holding a crate high, with three bars beside it and a hollow fourth. After a prediction, the hollow bar is named as what the winch put in, then the first bar as what the crate now holds, then the total line is drawn across them all. The last step swaps to a pendulum held aside and asks whether it holds energy before release.
See the whole ideathe big idea and the key word, in one place
The big idea
Energy is the ability to make something change.
Why it happensThe winch spent some of its own supply to lift the crate. What it spent did not vanish: most of it is up there in the crate, waiting.
Key word
- energy
- the ability to make something change: to lift, speed up, warm or light it; measured in joules, moved between stores, never created from nothing
About this modelThe bars move energy between stores; the total only changes when work is put in or taken out.
The bars move energy between stores; the total only changes when work is put in or taken out.
Ready to use it?
- Say whether a described object holds energy, and what change it could make.