Have you ever pushed a heavy bag up a sloping path instead of lifting it straight onto a step? Which felt easier?

Today we will feel how two simple machines, a ramp and a lever, help a small force do a big job.

I wonder whether a slope or a tipping bar can make a heavy book feel easier to lift.

Which do you think will feel easier: lifting a book straight up, or sliding it up a ramp? Could a stiff bar help us lift with one finger?

In your group, set up two simple machines from the kit on your table.

Ramp: lean the smooth board from the desk up onto a low stack of books so the slope is gentle. Check it is steady.

Lever: rest the wooden ruler across the marker or eraser so it can tip like a seesaw. Put the rest nearer the book end. Place the book on the short end. The end with no book is the free end: the end you will press.

We are investigating: How does lifting with a ramp or a lever compare with lifting straight up?

First, say your prediction out loud to your group: which of the three ways will feel easiest, and why?

Then try each test in order:

1. Straight lift: lift the book straight up from the desk to the height of your ramp top. Notice how hard the effort feels.
2. Ramp: slide the same book gently up the ramp to the same height. Notice how hard the effort feels now.
3. Lever: with the book on the short end, press the free end (the end with no book) with one finger until the book rises. If it will not rise, slide the rest a little closer to the book and try one finger again.