Ready when you are

The grown-up weighs three times as much. Where can the child sit to balance them?

Same sled, same hill. So why does one stop sooner?

How can a car stop without crushing its passenger?

Build a bridge. Then drive a lorry over it.

The ground is about to shake. Build something that survives.

Turn this little wheel. Make that big one crawl.

This lump of clay sinks. Make it float.

Can one folded wing fly farther?

Can you bounce light around the corner?

Lift the heavy crate with one hand.

The target is far away. What angle do you fire at?

One bulb is bright. Add another and both go dim. Why?