How much salt would I need to float in my bath?
Eureka! You can float in your bathtub by increasing the water's density. However, you're going to need an awful lot of salt.
Asked by: Richard O'Neill, Glasgow
As Archimedes showed over 2200 years ago, the trick lies in boosting the density of the bathwater until it exceeds that of your body. The easiest way to do that is to add salt to the water. But it requires a lot of the stuff: around 30kg in a standard bath-tub.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
Authors
Subscription offer
Subscribe and try your first 3 issues for just £5. After your introductory period you will pay just £22.99 every 6 issues by Direct Debit. Receive every issue delivered direct to your door with FREE UK delivery.
