Marvin & Milo

Facing pressure

Facing pressure

  

 

What you need:

A balloon

A little water

Two plastic cups

A friend

 

Instructions

Blow up the balloon to grapefruit size. Get your friend to wet the rims of the cups and hold them firmly against the balloon, one on each side.

Inflate the balloon to normal size then ask your friend to let go of the cups.

 

Results & explanation

The cups will stick tightly to the balloon without help, and if you draw a face on the balloon the cups it will look like ears.

At first the balloon dips deep into each cup, but it flattens outas you inflate it, taking up less space in the cups, so the air pressure inside them drops. The air pressure outside them is unchanged, so it presses them firmly against the balloon.

See previous cartoons

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Mirror magic

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Unsliced ice

Free fluid

Heavy atmosphere

Dogged drifter

Remote detector

Free fall ride

Electric slime

Pressure fountain

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