What you need

• A round biscuit tin (or similar container)
• A ramp or slope
• A lump of plasticine

Instructions

1. Attach a large-fist-sized lump of plasticine to the inside of the wall of the tin at the seam and put the lid on
2. With the seam facing upwards but towards the top of the slope, put the tin on its side at the bottom of the slope and hold it in place
3. Let go

Results and Explanation

The weight of the plasticine creates a turning force on the tin that levers it up the hill when you let go, and makes it look as though you're defying gravity.

These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.