# Pull tab of beverage containers

1. Aug 27, 2008

### noppawit

Beverage engineering. The pull tab was a major advance in the engineering design of beverage containers. The tab pivots on a central bolt in the can's top. When you pull upward on one end of the tab, the other end presses downward on a portion of the can's top that has been scored. If you pull upward with a 10N force, approximately what is the magnitude of the force applied to the scored section? (You will need to examine a can with a pull tab.)

After I measure the pull tab, I got:
Pull tab length is 2.5cm
From pulling zone to pivot is 1.75cm, let it = R
and from pivot to pressing zone is 0.75, let it = r

Given, pull upward 10N

Can I calculate by using
F1R = F2r
10 * 1.75 = 0.75 * F2
Fpressing = 23.33N

Is this correct?

2. Aug 27, 2008

### Redbelly98

Staff Emeritus
Yes it's correct, given the numbers you have for R and r.

3. Aug 27, 2008

### tiny-tim

did i hear the sound of a beer can being opened … ?

Hi noppawit!

Looks good!

It's a lever, so the gearing is the ratio of the lengths …

hmm … now pull one for me!

EDIT: oh … and one for Redbelly98 too!