Flying Toilet Paper

What To Do

Setting up this demonstration is a little fiddly. You will need a paint brush roller holder, a leaf blower and some good strong tape. Tape the handle of the paint roller on the bottom of the leaf blower outlet at the front so that the roller portion is positioned in front of and a little below the centre of the outlet.

This is one of the easiest demonstrations to do. Place a toilet roll onto the paint brush roller, plug in the blower, aim it upwards, turn it on and watch as the toilet paper is propelled across the room.

The Science

The air from the blower, blows across the top of the toilet roll and gets squeezed up by the curve of the toilet roll. This causes the air to go faster and also causes the air pressure to drop. The drop in air pressure on top and the normal (higher) pressure underneath makes the end of the toilet paper lift up just like the lift generated by an aeroplane wing. This is known as the Bernoulli Principle). As the toilet paper end starts flapping around the constant flow of air from the leaf blower pushes against it causing the paper to fly away – quickly. Have fun!