The weather is very hot. Use a balance and a scale to measure the density of a cube of uniform mass. The scale is made of a metal material which is sensitive to temperature The side length of the cube measured by the scale will be smaller than that measured by the standard room temperature

The weather is very hot. Use a balance and a scale to measure the density of a cube of uniform mass. The scale is made of a metal material which is sensitive to temperature The side length of the cube measured by the scale will be smaller than that measured by the standard room temperature

The side length of the cube is smaller than the actual length
The measured density is larger than the actual density
The measured density and side length are at this temperature, so only the influence of temperature on the scale is considered

36. For the existing balance, measuring cylinder, water, empty bottle, thin line, scale and cube metal block, please select appropriate equipment from the following instruments to measure the density of the metal block
Experimental project
The experimental method is to select the expression of the physical quantity density required by the instrument
Experiment method 1
Experiment method 2
Experiment method 3

1、 Experimental equipment: balance, measuring cylinder, water, thin wire, metal block;
Operation steps: 1. Measure the mass (m) of the metal block with the adjusted balance;
2. Fill the measuring cylinder with proper amount of water and measure the volume of water (V1);
3. Slowly immerse the metal block in the water in the measuring cylinder with a thin wire, and measure the total volume of water and metal block (V2);
4. The density of the metal block is: ρ = m / (v2-v1)
2、 Experimental equipment: balance, metal block, scale;
The operation steps are as follows: 1. Measure the mass (m) of the metal block with the adjusted vote;
2. Measure the edge length (a) of the metal block with a scale;
3. The density of the metal block is: ρ = m / A & sup3;
3、 Experimental equipment: balance, water, metal block, empty bottle;
The operation steps are as follows: 1. Measure the mass (m) of the metal block with the adjusted vote;
2. Fill the bottle with "full" water and measure the total mass (M ');
3. Measure the total mass (M '') of the metal block "immersed" in the water in the bottle with a thin wire;
4. The volume of metal block is equal to the volume of water discharged by metal block: V gold = V row = m row / ρ water = [M '- (M' '- M)] / ρ water;
5. The density of the metal block is: ρ = m, ρ water / [M '- (M' '- M)]

Measuring the length of a disorderly thin wire
There is a mess of thin wire that can not be straightened out. There is a round pencil, a scale and a large cup. Use these tools to measure its length

First, use a certain amount of water left in the measuring cup, and remember the volume. Then take a certain length of wire with a scale, and put it into the measuring cup. According to the change of water volume in the measuring cup, measure the ratio of the dead length of the metal to the volume, and then put the whole ball of wire into the measuring cup to measure the volume, Then multiply it by the ratio (length to volume) just measured, so that the length can be measured simply and accurately