It is generally known that a cubic meter of water is about one ton, so how can its density be calculated? If the density of water is 1, what is the density of wood and marble? When did you learn these questions? What textbook did you come from?

Density = mass / volume (not weight!)
The density of marble is about 3 g / cm3
The density of wood varies greatly, which will be given in the general topic
Density is from the second year of junior high school. It's from physics books

Measuring the density of pebbles
Equipment: Xiaoping, measuring cylinder, water
Put Jiang Sheng into the measuring cylinder to make it float
2. Put the pebble into the duckweed, but it is still not floating, and read the corresponding scale of the water surface as v2
3. Take the stone out of the bottle, put it into the water, and read the corresponding scale of the water surface as v3
expression
Ρ = (v2-v1 / v3-v1) * Ρ
Ask the big God to help analyze how the expression comes out, thank you

∵ V1 = V bottle + V water
V3 = V bottle + V water + V stone
So V stone = v3-v1
Because v2-v1 = △ V
Δ f floating = P water g △ V
Because △ f = G
So m stone = P water (v2-v1)

Calculate the apparent density and bulk density of the stone
After the stone is completely dried, its mass is 482g. Put it into the measuring cylinder with water. After the stone is saturated with water for a certain period of time, the water surface of the measuring cylinder rises from the original 452cm scale to 630cm scale. Take out the stone, wipe the water on the surface, and the mass is 487g. Calculate the apparent density and bulk density of the stone

First of all, the apparent density refers to the mass scale of unit volume in natural state to determine whether it is cm or ml. if it is cm, the volume of stone V1 = π R2 * (630-452) if it is ml, the direct volume of stone V1 = 630-452, and the apparent density = 482 / V1
Let's talk about the bulk density. The bulk density refers to a large range of apparent density. If you want to ask for other densities, please explain in detail

A cuboid has a volume of 54 cubic meters and a height of 0.9 meters. What is the bottom area of the cuboid?

It's 60

The bottom area of a cuboid is 80 square centimeters, the height is 7 centimeters, and its volume is______ Cubic centimeter

80 × 7 = 560 (cubic centimeter). A: its volume is 560 cubic centimeter

A cuboid bottom area is 27 square decimeters, 5.9 decimeters high, his volume is how many cubic meters

27x5.9 = 15.93 cubic decimeter

The area of the bottom of a cuboid is 4 square decimeters, the length is 6 decimeters, and its volume is () cubic meters,

It's the area of the cross section
Otherwise, we can't find out
Volume: 4 × 6 = 24 cubic decimeter = 0.024 cubic meter

The volume of a cuboid is 3 / 25 cubic meters, its width is 1 / 2 meter, its height is 2 / 5 meter, how many meters is its length? How many square meters is its bottom area

Cuboid volume = length * width * height, so set the formula, length is 3 / 5 meters, bottom area = length * width, so bottom area is 3 / 10 square meters

The volume of a rectangle is three twentieth of a cubic meter, and its width is three fifths of a meter. What is the bottom area of the rectangle

Bottom area = 3 / 20 △ 3 / 5 = 1 / 4 M2

A rectangle with a volume of three tenths of a cubic meter, three eighths of the left area, two fifths of the front area, and a surface area of [] square meters?

Let the cuboid be a in length, B in width and C in height,
ABC = 3 / 10; AC = 2 / 5; BC = 3 / 8
① Divide by 2, B = 3 / 4; divide by 3, a = 4 / 5, ab = 3 / 5
Surface area = 2 (AB + BC + AC) = 11 / 4

It is generally known that a cubic meter of water is about one ton, so how can its density be calculated? If the density of water is 1, what is the density of wood and marble? When did you learn these questions? What textbook did you come from?