Cardboard comes in different weights, depending on thickness, whether it is corrogated (i.e. with spaces), pressed, etc. So, the answer would depend first on the type and weight of the cardboard.
Regardless of type of cardboard or the weight of the type, I would guess it would weigh far less than the CD and CD case together.
I would further guess it would weigh about or less than the plastic CD case without the CD, with both CD and and extra cardboard piece being the same dimensions (height+width) and if the cardboard was thin.
Lifes
It has 156 cubic inches
Rocks vary greatly in density and weight. A piece of pumice that size could weigh maybe an ounce, while a lead-laden rock may weigh many times that, maybe closer to a pound.
Impossible to answer !... the size of a person's shoes has no bearing on how much they weigh.
Depends on size
well it really depends on the size of the 5 year old
The weight of a puzzle piece varies depending on the material and size of the piece. On average, a standard cardboard puzzle piece weighs less than a gram, while a wooden puzzle piece can weigh around 2-3 grams.
The weight of a cardboard box can vary depending on the size and thickness of the box. On average, a small cardboard box may weigh around 0.2-0.5 pounds, while a larger box can weigh 1-2 pounds.
Not enough information to answer.... There is no 'standard' weight for cardboard. A box with walls of 4mm thickness will weigh less than the same size box, with walls of 6mm thickness.
Depends on the size and quality of the paper.
It has 156 cubic inches
The weight of a piece of card stock can vary depending on its size and thickness, but on average a standard letter sized piece (8.5 x 11 inches) might weigh around 5-8 grams.
The weight of an empty container can vary depending on its size, material, and design. On average, most empty containers weigh between a few ounces to several pounds.
How long is a piece of string? You have provided no size and density information, so the question is unanswerable.
The weight of a poster can vary depending on its size and material. On average, a typical paper poster can weigh between 5-10 ounces, while larger or heavier posters made of materials like cardboard or foam board can weigh up to a few pounds.
Gold
A single piece of construction paper typically weighs about 0.18 ounces. This weight can vary slightly depending on the thickness and size of the paper.
You can weigh any size.