What are the methods for measuring or calculating density?

Measure the density of liquids.

1. Conventional Law.

1.Main equipment: balance, graduated cylinder.

2.Measurement Steps:

1) Fill a beaker with an appropriate amount of unknown liquid, put it on an adjusted balance, and weigh its mass m1;

2) pour some unknown liquid in the beaker and measure its volume v in a graduated cylinder;

3) Place the beakers containing the remaining unknown liquid on the balance and measure their mass m23Calculation results: according to .

Second, the density bottle method.

1.Main equipment: balance, unknown liquid, glass bottle, water.

2.Measurement Steps:

1) Use an adjusted balance to measure the mass m0 of the empty bottle

2) Fill empty bottles with water and measure their total mass m1

3) Pour out the water, fill the empty bottles with unknown liquids, and measure their mass m23Calculation results:

The quality of the liquid:

Volume of liquid:

Density of liquid:

3. Density meter method.

1.Main equipment: self-made density meter, unknown liquid, graduated cylinder.

2.Measurement Steps:

1) Wrap the wire around the lower end of a thin wooden stick to make a simple density meter;

2) Put an appropriate amount of water in the graduated cylinder, let the density meter float in the water, and measure its volume v water in the water.

3) Put an appropriate amount of unknown liquid in the graduated cylinder, let the density meter float in the liquid, and measure its volume v liquid in the liquid.

3.Calculation results:

Fourth, the buoyancy method.

1.Main equipment: spring dynamometer, water, metal block, unknown liquid.

2.Measurement Steps:

1) Use a spring dynamometer to measure the gravity g0 of the metal block in the air;

2) Use an elastic dynamometer to measure the gravity g1 of the metal block submerged in water;

3) Use a spring dynamometer to measure the gravitational force g2 of a metal block immersed in an unknown liquid.

3.Calculation results:

5. Floating body method.

1.Main equipment: Scale, unknown liquid, water, cube of wood.

2.Measurement Steps:

1) Float the wooden block flat in the water and measure the depth of the wooden block immersed in the water h12) Float the wooden block flat in the liquid and measure the depth of the wooden block immersed in the liquid h23Calculation results:

Measurement of solids, etc.

1. Routine measurement:

1. Use graduated cylinders, tray balances, and weights to measure. For example, in the textbook, the density of stones and salt water are measured.

2. Use pallet balances, weights, and scales to measure the density of regular objects.

3. Use a density meter to measure the density of liquid.

2. Special Measurements:

1. Use tray balances, weights, water, mineral water bottles to measure the density of milk.

2. Use tray balances, weights, water, and beakers to measure the density of metal particles.

3. Use a graduated cylinder and water to measure the density of plasticine.

4. Use spring dynamometer, water, and beaker to measure the density of iron.

5. Use a scale, water, beaker, and string to measure the density of the ore.

Find two** and see for yourself and.

The six methods of density measurement include weighing method, bibi cup method, Archimedes' law, buoyancy method (1), buoyancy method (2), and density meter method.

Weighing method. 1. Use a balance to weigh the mass of the metal block.

2. Inject an appropriate amount of water into the graduated cylinder, and the reading volume is V1.

3. Tie the metal block with a string and put it into a graduated cylinder, immerse it, and read the volume as V2. Evaluate the expression: =m (v2-v1).

Gravity cup method. <>

1. Fill the beaker with water and place it on the balance to weigh the mass m1.

2. Gently put the block into the water, overflow part of the water, and then put the beaker on the balance to weigh the mass m.

3. Take out the metal block, place the beaker on the balance and weigh the mass m3 of the beaker and the remaining water. Calculation expression: = water (m2-m3) (m1-m3).

Archimedes' Law.

1. Tie the metal block with a thin rope and weigh the gravity g of the metal block with a spring scale.

2. Completely immerse the metal block in water, and weigh the apparent weight g of the metal block in the water with a spring scale; Calculation expression: =g water (g-g).

Buoyancy method (1).

1. Inject an appropriate amount of water into the graduated cylinder, and the reading volume is V1.

2. Put the wooden block into the water to float, and read the volume v2 after being still.

3. Insert the wooden block with a fine needle, completely immerse the wooden block in water, and read the volume as V3. Calculation expression: = water(v2-v1) (v3-v1).

Buoyancy method (ii).

1. Put an appropriate amount of water in the cylinder cup, and then gently put the plastic cup mouth facing up, let it float, and measure the height of the water in the cup h1 with a scale ruler.

2. Gently put the small stones into the cup to float, and measure the height of the water h2 with a scale.

3. Take out the small stones from the cup, put them in the water and sink them, and measure the height of the water h3 with a scale. Calculation expression: = water (h2-h1) (h3-h1).

Density meter method. 1. Pour an appropriate amount of water into the glass, gently put the eggs in, and the eggs will sink.

2. Gradually add salt to the water, stir with a density meter while adding until the egg floats, and measure the density of the salt water with a density meter, which is equal to the density of the egg.

Weighing method: equipment: balance, measuring cylinder, water, metal block, string. Steps:

1. Use a balance to weigh the mass of the metal block;

Weigh 2, inject an appropriate amount of water into the graduated cylinder, read the volume of v1, weigh 3, tie the metal block with a string and put it into the graduated cylinder, immersion, the reading volume is v2

Weigh the calculation expression: =m (v2-v1).

Weighing the Gravity Cup Method:

Weighing equipment: beaker, water, metal block, balance. Steps:

Weigh 1, fill the beaker with water, put it on the balance and weigh the mass as m1;

Weigh 2, gently put the subordinate block into the water, overflow part of the water, and then put the beaker on the balance to weigh the mass as m2;

Weigh 3. Take out the metal block, put the beaker on the balance and weigh the mass of the beaker and the remaining water m3

Called the calculation expression: = water.

Called Archimedes' Law:

Weighing equipment: spring scales, metal blocks, water, strings. Steps:

Weigh 1, tie the metal block with a string, and weigh the gravity g of the metal block with a spring scale;

2. Completely immerse the metal block in water, and weigh the apparent weight g of the metal block in the water with a spring scale;

Called the calculation expression: =g water (g-g).

Called the buoyancy method (a):

Weighing equipment: wooden blocks, water, fine needles, graduated cylinders. Steps:

1. Inject an appropriate amount of water into the graduated cylinder, and the readout volume is V1;

2. Put the wooden block into the water, float, and read the volume v2 after stationing;

Weigh 3. Insert the wooden block with a fine needle, completely immerse the wooden block in water, and read the volume as V3= Water.

Weighing buoyancy method (2): equipment: scale, cylinder cup, water, small plastic cup, small stone. Steps:

Weigh 1. Put an appropriate amount of water in the cylinder cup, and then gently put the mouth of the plastic cup upwards to float, and measure the height of the water in the cup h1 with a scale;

Weigh 2, gently put the small stone into the cup, float, and measure the height of the water h2 with a scale; Take the small stones out of the cup, put them in the water, sink them, and measure the height of the water h3 with a scaleCalculation expression: = water (h2-h1) (h3-h1) density meter method:

Equipment: eggs, density meter, water, salt, glass. Steps:

1. Pour an appropriate amount of water into the glass, gently put the egg in, and sink the egg;

2. Gradually add salt to the water, stir with a density meter while adding until the egg floats, and measure the density of the brine with a density meter, which is equal to the density of the egg.