The answer depends on the type of wood used (different woods have different density levels) and whether or not you mean a full sheet (4' X 8').
245 lbs
A half inch thick tempered glass will weigh 6.75 lb/ft2. With that much thickness, it can support much of the weight of possibly a small child or small animal.
1 gram
between 68 and 70 lbs
about 10to 12 pounds If we are talking about 4' x 8' sheets, the answer is more like 45 pounds, although it can vary quite a bit by type of wood used, grade and interior versus exterior.
i raised a painted lady butterfly in grade 3 and they are like a inch or half a inch
16 units
It depends what the "ply" value is ... the number of layers glued together. For instance, 1/2" plywood is going to be lighter then 3/4" plywood. A common rule of thumb is a 4x8 foot sheet of 1/4" fir plywood weighs 25 pounds. There are 32 square feet in a sheet, so a square foot of 1/4" fir plywood weighs about 0.78 pounds. Since 1/2" is twice as thick as 1/4", 1/2" fir plywood weighs twice as much, or 1.56 lbs, and 3/4" three times as much, or about 2.34 lbs. Fir plywood is common, but other species are available. Weight varies considerably between species of wood, so be aware the weight of plywood of different species can be different.
watch the the Simpsons
A near-spherical meatball two inches in diameter should weigh slightly under two and one-half ounces (70 grams).
A 74 inch sturgeon would weigh about 126 pounds.
when asking this question you first need to take into account that plywood comes in different thicknesses therefore weight per particualr thickness of sheet plywood will vary-- in my opinion/ without fact and research / a sheet of 1/2 inch plywood may way about 16 lbs. while a 3/4 inch plywood sheet may way 70 lbs.