1Two ideas you'll need
Height is stored "go" — and a drop spends it as speed
A coaster cart has no engine after the start. It runs on one thing: go-power. Watch where it comes from and where it goes.
Height = stored go-power
Lift the cart up high and you load it with go-power, just sitting there waiting to be spent. The higher you lift it, the more it holds.
A drop spends it as speed
Roll downhill and the height turns into speed. Climb back up and the speed turns back into height. It's the same go-power, just changing its form.
2Two kinds of next hill
A hill you can afford vs a hill too dear to buy
The cart starts at one height. Whether it clears the next hill comes down to one thing — is that hill lower or higher than where it began?
A hill you can afford
Lower than where the cart started — so it sails over with go-power to spare.
A hill too dear to buy
Higher than where the cart started — so it runs out of go partway up and rolls back.
3Your turn — build the first hill
Lift the cart and watch go-power swap between speed and height
Drag to set how high the first hill is, then let the cart go. The second hill stays the same. Watch the bar split go-power into speed and height as it rides — it's always the same total.
The cart's go-power right nowfull tank
First hill height: tall
4Now try to beat the budget
Does a heavier cart climb higher? 🎢
Keep the track and release point fixed. First run one cart, then load it to twice the mass. This smooth-track model leaves out friction and air drag so we can test mass on its own.
Guess before you let it go
Two carts start from the same height with no push. One has twice the mass. On this smooth track, will the heavier cart climb higher on the next hill?