What does a 2 inch long paper clip weigh?

Answer 1

0.4 grams. Wondering how I know?

Here's how:

Put a pen on a flat surface. Then tape the pen to surface (I used electrical tape because it comes off easy)

Take a ruler (preferably metal) and lay it on the pen.

Next balance the ruler on the pen and then tape it down in the middle. (at this point the tape looks like a sideways H)

I put a dollar at the very end of one side of the ruler (because it weighs a gram)

then began adding paper clips at the very end of the other side

It took two and a half paper clips to balance the dollar bill exactly.

One of these paper clips must weigh 0.4

grams. (1g / 2.5 clips = 0.4 g)