Idea 1of 5Builds onPaying with a pushEarth pulls everything
Banked by height
Lift a 2 kg ball to 10 m. What is banked?
Today you'll discover
- where the work of lifting goes
- why height is a kind of savings
- the name of the store
Think firstA 2 kg ball, lifted to 10 m and held
You lifted the ball 10 m with 196 J of work. Where is that energy now?
Decide first, then press Next. Read the first bar against the lift.
A ledger with a small drawing of a ball held high and three bars beside it. After a prediction, the first bar, energy banked by height, is labelled with the value of the lifting work. The last step lifts the ball twice as high and asks for the stored energy.
See the whole ideathe big idea and the key word, in one place
The big idea
Height banks energy: potential energy, m g h.
Easy to get wrongA still object can hold energy. Motion is one store; height is another. The held ball has none of the first and plenty of the second.
Key word
- potential energy
- energy stored by position; gravitational potential energy Eg = m g h, counted from a chosen zero height
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?
- Find the gravitational potential energy of a mass at a given height.