(1) making a measuring cup, quantitatively pouring water into the bottle with the existing measuring cylinder in the laboratory, and engraving the scale; ② Punch small holes with the same size at different heights of the measuring wall of the bottle as a liquid side pressure tester. After pouring water, it can be intuitively reflected from the water flow that the pressure inside the liquid increases with the increase of depth.

(1) Self-made measuring cylinder mainly draws scale lines. We can choose a flat glass, put white tape on it and mark the scale line.

(2) If the container is even in thickness, measure 1ml water with a measuring cylinder and pour it into the glass, which is the graduation line of 1ml, then measure 100ml water with a measuring cylinder and pour it into the glass, and divide the two graduation lines into 65438+.

If the thickness of the container is uneven: measure 1 ml, 2 ml, 3 ml, 4 ml, 5 ml, etc. Use the measuring range to measure for many times, and mark the scale lines in turn.

(3) Measuring the density of rubber:

(1) Measure the quality of rubber with a balance, and record it as m;

(2) pour a proper amount of water into the measuring cylinder, and read the volume of water, and record it as v1;

(3) Tie the rubber with a thin thread, put the rubber into the water, immerse the rubber in the water, and read out the total volume of the rubber and the water, and record it as v2;

④ Density of rubber ρ =

m

V 2 - V 1

Determine the density of milk:

① Put the milk into a beaker, and measure the quality of the beaker and milk with a balance, and record it as m1;

(2) part of the milk in the beaker is poured into a measuring cylinder, and the volume of the milk is measured, and recorded as V;

③ Measure the mass of the remaining milk and beaker, and record it as m2;

④ The density of milk ρ =

M 1 m2