1. If this piece of wood is sawed into three sections at 3: 4: 5.

The shortest block length should be L=60/(3+4+5)*3= 15dm.

Cylinder volume v = s * l = π r 2 * l = π * 22 *15 = 60 π =188.5dm?

2. The volume of a square copper block is 8 3 = 512cm?

Is the area of the bottom of the plumb hammer S=πR? =π*5? =25π cm？

So the height is 5 12/(25π)=6.52cm.

Hope to adopt, don't understand and ask again.