Slice one ping pong ball in half.
Fill up the half of the ping pong ball with water.
Empty the water from the ping pong ball into a measuring cup.
Measure the amount of water in mL and multiply it by 2, ( there are two halves ).
I worked it out, and found that one mole of ping pong balls would cover the United States to a depth of 4208 km. This may be wrong though.
Use a balance or a set of scales
According to a couple of sources I looked at (e.g. www.brookings.k12.sd.us/krscience/open/cells/moles.ppt), a mole of ping pong balls would cover the entire surface of the earth to a depth of 60 miles!
about 144 ping pong balls are in a gross.
10 ping pong balls
Trent, and Duncan have the ping-pong balls and i think Harold does too.
No they do not.
Sure it can. But you'll need a lot a lot of ping pong balls- I believe the ratio is about 1 pound per 15 ping pong balls... then you can lift just about anything.
There is insufficient information in the question to answer it. How are the ping-pong balls hanging? By what? Are they touching? What is the orientation of the straw with respect to the ping-pong balls? Please restate the question.