METRIC MEASURES OF WEIGHT

72. Written.

The unit of weight is the gram. It is the weight of 1 cubic centimeter of water at 4 degrees centigrade.

Since a liter contains 1000 cu. cm, a liter of water weighs a kilogram. Since a cubic meter contains 1000 liters, a cubic meter of water weighs a ton.

In studying weight, procure, or make, a pair of balances (see page 109, Part I) and have pupils estimate the weight of various objects in the schoolroom, and then test their estimates with the balances.

1. Express in grams the weight of 1 liter of water; of 16.5 liters; of 125.25 liters; of 2.167 1; of .075 1.

2. How many grams are there in .495 Kg? In 4.607 Kg? In 25.02 Kg? In 425.04 Kg?

3. How many kilograms are there in 7562 grams? 47,065 g? In 25 g? In 2.5 quintals? In .45 Q?

4. Change 1675 Kg to Q; 407 Q to Kg; 95 mg to g.

In

5. What will the water weigh that fills a tank 2.4 m long, 35 cm wide, and 24 cm deep?

6. At P15.60 a metric ton, what will 750 Kg of coal cost?

7. Change to Kg and add: 1765 g; .2054 M T; .4269 Q.

1. A cubic centimeter of water weighs 1 gram. If a cubic centimeter of iron weighs 7.8 grams, iron is how many times as heavy as water?

The specific gravity (sp. gr.) of a substance is its weight as compared with the weight of an equal volume of water. The specific gravity of iron is 7.8.

2. What is the weight of 400 cubic centimeters of lead, if the sp. gr. of lead is 11.34?

3. If the specific gravity of mercury is 13.6, what will 250 cu. cm of mercury weigh? Analyze.

4. Find the weight of a piece of wood 20 cm square and 3 m long, if the specific gravity of the wood is .92.

5. Find the weight of the petroleum (sp. gr. .82) that fills a tin can 24 cm long, 24 cm wide, and 25 cm deep.

6. If 4 liters of milk weigh 4.59 Kg, what is the specific gravity of milk?

7. The oil that fills a can 20 cm by 20 cm by 30 cm weighs 9.9 Kg. What is the specific gravity of the oil?

8. How much does a piece of timber weigh that is 24 cm square and 5 m long, if the sp. gr. of the wood is .9?

9. If the specific gravity of a piece of zinc which weighs 1080 Kg is 7.2, what is its volume in cubic centimeters?

10. What is the specific gravity of silver, if 240 cu. cm of it weigh 2.52 Kg? Analyze.

11. Find the weight of 40 liters of alcohol having a specific gravity of .81.

12. A can of milk (sp. gr. 1.02) weighs 30.25 Kg. The empty can weighs 4.75 Kg. How many 1 of milk are there in the can?

74. Written.

METRIC REVIEW PROBLEMS

1. The tunnel of a coal mine averaged 3 m by 4 m and was 255 m long. How much coal and earth had been removed? If the weight of the material removed

was 1100 Kg per cu. m, and of it was coal, how many tons of coal were obtained?

2. If the cars in which the coal was carried from the tunnel had an average capacity of 625 Kg, how many of these car loads would be needed to supply a vessel for a trip from Manila to Hongkong, if the

vessel consumed 25 tons per day and required 2 days to make the trip?

3. Find the cost of filling in a building lot 54 m long and 22.5 m wide to an average depth of 32 cm, at P1.85 per cu. m.

4. Find the cost of a field 250 m square at P 140 a Ha.

5. How many hektoliters of water will a rectangular cistern hold that is 1.3 m long, 90 cm wide, and 2.4 m deep?

6. What will be the weight of a load of 240 bricks, each 20 cm by 10 cm by 5 cm, if the sp. gr. of brick is 2.4?

7. What will it cost to paint the four walls of a room 5.5 m long, 4.5 m wide, and 4.2 m high, at P.28 a square meter?

8. How many bricks, each 20 cm by 10 cm by 5 cm, are there in a pile 2.2 m long, 1.4 m wide, and 1.2 m high?

9. A merchant bought 12.5 quintals of rice at P8.50 a quintal and sold it for P.11 a kilo. How much did he gain?

10. If a liter of oil weighs .92 of a kilo, what must I pay for 120 liters at P.80 a kilo?

11. What must be the depth of a box 60 cm long and 75 cm wide, that it may hold 180 liters?

12. If a man walks 90 m per minute, how long will it take him to walk 44.55 kilometers at the same rate?

13. A man paid P24.75 for a pile of wood 4.4 m long, 1.25 m wide, and 2 m high. How much did he pay per cubic meter?

14. A tank full of water weighs 2.25 Q. The tank weighs as much as the water it contains. What is the capacity of the tank in liters?

15. A block of stone 1.2 m long, 50 cm wide, and 22 cm thick weighs 316.8 Kg. What is its specific gravity?

16.

How many sq. m of zinc will it take to line the bottom and sides of a vat 3.9 m long, 1.2 wide, and .8 m deep?

17. What is the weight of the water in a tank if it takes 47 minutes to empty it at the rate of 125 1 a minute?

18. If rain falls 3 cm deep on the level, how many liters is that per sq. m? How many tons per Ha?

19. Find the weight of a bar of iron (sp. gr. 7.8) 6 m long, 12 cm wide, and 5 cm thick.

20. A jar weighs 6.5 Kg when empty and 23.7 Kg when half full of water. What is its capacity?

21. If soil is cultivated to a depth of 18 cm, how many cu. m of cultivated soil is that per Ha?

22. A lot 37 m wide contains .6 Ha. How long is it? What will it cost to fence it at P.14 per meter?

23. A bin 2.25 m long, 1.2 m wide, and 2.5 m deep, is full of rice. How much rice does it contain?

24. Find the weight of a block of stone 1 m long, 45 cm wide, and 24 cm thick, if the stone is 2.5 times as heavy as water.

75. Written.

1. Find the cost of planting a plantation of 13.5 Ha with coffee and the cacao trees necessary for shade, if the cost per

Ha is as follows: for plowing, 9 days' labor with carabao @ P1.85; for planting cacao seed, 4 days' labor @ P.65; cost of 7 gantas of cacao seed @ P.50; cost of 3333 coffee plants @ P1 per 100; for planting coffee, 10 days' labor @ P.60.

2. What will be the cost of caring for a coffee plantation of 14.7 Ha for three years, if the average annual cost per Ha is P 35?

3. At P.95 per picul find the cost of cleaning and sorting the coffee from a plantation of 18.9 Ha if the crop averages 16.4 piculs per Ha. What will the crop sell for at P 17.65 per picul?

4. During the years 1885-1890 the Philippine Islands exported coffee to the amount of 5,467,830 Kg, 7,156,388 Kg, 4,947,947 Kg, 6,289,255 Kg, 6,218,655 Kg, and 4,479,868 Kg. Find the total amount exported.

6. If coffee seeds are planted in a bed 6 m by 4 m, 15 cm apart in each direction, how many seeds are planted?