We would like to produce a lightweight epoxy part to provide thermal insulation. We have available hollow glass beads for which the outside diameter is 1/16 in. and the wall thickness is 0.001 in....

We would like to produce a lightweight

epoxy part to provide thermal insulation.

We have available hollow glass beads for

which the outside diameter is 1/16 in. and

the wall thickness is 0.001 in. Determine

the weight and number of beads that

must be added to the epoxy to produce a

one-pound composite with a density of

0.65 g/cm3. The density of the glass is

2.5 g/cm3 and that of the epoxy is 1.25 g/cm3.