In a lab lesson that practises measuring the mass of a stone with a balance, there is a group of bal

2: Add weights and move the code 3: Remove the stones and weights, and add fine sand to the left plate of the balance 4: The mass of the weight plus the scale of the code is subtracting the mass of the fine sand (the code can not be considered if it is not particularly emphasized in the question).

1. Put an appropriate amount of water in the graduated cylinder (to ensure that the water will not overflow after the small stone is put in, and the stone can be submerged when the source is lifted), and read out the scale value (that is, the volume of water) v1 of the water surface at this time.

2. Tie the small stone with a thin wire and carefully put it into the water of the graduated cylinder and immerse it, and read the scale value v2 of the water surface at this time when it is stable.

Obviously, the volume of the small stone is v v2 v1 .

Note: If the balance is used to weigh the mass m of the pure block of the stone, the density of its split plexus m v m v2 v1 ) can also be obtained

First measure a certain volume of water in the graduated cylinder and record the result, then use a thin wire to put the stone into the measuring cylinder filled with water (the stone is required to be completely immersed in the water), and then observe how much the water level in the two buckets rises, and the volume of the water with the liquid level rising is definitely the volume of the stone!!

Drainage measures the density of water that is known.

Density shield sum = mass volume.

The volume of this stone = total volume - water volume = 65-50 = 15 (g cm).

The density of this stone = g divided by the difference of 15 g cm = cubic centimeter to talk about the conjugation.

Density sensitivity of irregular stones = mass volume of stone sparkling celery blocks.

Density of irregular stone bridge eggplant blocks = g cm cubic.

1) According to the use method and operation steps of the split balance, it can be seen that in the process of measuring the mass of small stones with the balance, the reasonable order is a, c, and b

2) It can be seen from Figure A (b) that the mass of the small stone is m=50g+20g+3) As shown in Figure B, the volume of the small stone v=60ml-40ml=20ml=20cm3

The density of a small stone block is =m

kg m3 so the answer is: (1) acb; （2）；（3）

According to the adjustment of the balance and the rules for the use of trembling, it can be known:

1) Place the balance on the horizontal tabletop, and the balance base should be adjusted to the level first;

2) Move the mountainside code to the "0" tick line at the left end of the weighing scale; The next operation is: adjust the balance nut so that the pointer points to the ** of the index dial;

3) Place the stone to be measured on the left plate and place the weight in the right plate, and balance the balance again by adding or subtracting the weight and moving the yard

Therefore, the answer is: (1) the base of the balance; (2) Adjust the balance nut so that the pointer points to the index plate;

3) By adding and subtracting weights and moving the code; （4）67．

(1) Before the balance is balanced, the game code must be dialed to the zero tick mark;

2) Now the pointer is biased to the left, so the balance nut should be adjusted to the right;

3) Adjust the balance nut relative to adding a weight with a relatively small mass on the right plate;

4) The mass of the small stone is m=50g+;

5) The total volume of water and stones in the graduated cylinder is 30cm3, so the volume of the stones is v=30cm3

10cm320cm3

6) The density of the stone block is =m

v=20cm=

kg m3, so the answer is: (1) the code is not moved to the zero line of the ruler; (2) right; (3) Add a weight with a smaller mass to the right disk;

Weigh; 1) If you measure the volume of the stone first, and then measure the quality of the stone, the stone will be stained with water, so that the mass of the stone is large, affecting the measurement results, after analysis, the correct order is:

d Weigh the mass m of a small stone on a balance

c Pour an appropriate amount of water into the graduated cylinder, measure the volume of water v1a Tie the stone with a thin wire, gently put it into the water in the graduated cylinder, measure the total volume of water and stone v2b and calculate the density of the stone

According to the reading method of the balance Bizhan Cave, the mass of the object is equal to the mass of the weight plus the scale opposite the code, that is, m=50g+2g=52g; Repentance.

According to the reading method of the graduated cylinder, the line of sight is parallel to the bottom of the concave surface of the liquid surface, and the volume of the water of the graduated cylinder is v120cm3 and the body of the small stone v2

40cm3 Stone. v2v1

40cm320cm3

20cm3 according to the density formula = mv stone.

52g20cm

kg m3 so the answer is: dcab; reduce weights; Mobile travel code; ③52；20；