Question: How many rolls of cellotape would it take to stick someone to the ceiling. I was thinking of trying it. I had a go with my cat but unfortunatly sacrafices must be made for science.

Jim Caryl answered on 12 Jun 2011:

Ha, well, I’ve got no idea either! But I’ve never let not knowing something get in the way of wanting to try something; it would actually be possible to work out, or at least get to near the right number.

Imagine how long a strip of tape you’d need to go from the left-side to the right-side of a person, but also extend some distance to either side. Then half-way along the strip, try securing objects of increasing weight. When you find one that can’t be held by the strip of tape, weigh it on the weighing scales. Then you just need to work out how many times that weight goes into the weight of the person you’d want to sellotape to the ceiling, probably quite a lot, but whatever number that is will be the number of strips you’d need; if you know the length of the strip, then you can work out how much sellotape you’d need as most sellotapes tell you how long they are.

You could also work out how much ‘stick’ there is in every 2.5 x 2.5 cm square (square inch) of sellotape, using a similar method to above, checking different weights, but all must only be stuck onto a 2.5 x 2.5 cm square. Once you know how much weight a 2.5 x 2.5 cm square will hold, you can work out how many squares (the ‘area’) that would be needed to hold the weight of a person – I’m betting this area would be more than you could fit on a person, so this tells you about how far each side of the person the tape would need to extend.

You’d have to try different variations of whether you go from side-to-side or criss-cross with the tape, and you’d have to ensure that the ceiling was of a material that you can stick things to.

In any case, that’s two ways of working it out, I’m sure there are better (I’m no physicist – try asking one), but I don’t recommend trying it with your cat (poor cat!), or a person; I’m also pretty sure it’d pull the wallpaper off the ceiling, so I don’t think your folks would be pleased. Sometimes it’s just fun to figure these things out ‘in theory’, it’s what we call a ‘back of the envelope calculation’.