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PROBLEMS-PHYSICAL MEASUREMENTS

The table shows the average height and weight of Boston school-children.

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I. From the measurements for boys find the increase in height for each successive year; the increase in weight.

2. From the measurements for girls find the increase in height for each successive year; the increase in weight.

3. What is the total increase in the height of boys during the period from 9 to 12 years of age? From 12 to 15? From 15 to 18? During what period is the increase greatest?

4. What is the total increase in the height of girls during the period from 9 to 12 years of age? From 12 to 15? From 15 to 18? During what period is the increase greatest?

5. What is the total increase in the weight of boys during the period from 9 to 12 years of age? From 12 to 15? From 15 to 18? During what period is the increase greatest?

6. What is the total increase in the weight of girls during the period from 9 to 12 years of age? From 12 to 15? From 15 to 18? During what period is the increase greatest?

PHYSICAL MEASUREMENT

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The upper line in the figure represents the rate of growth of a boy from 9 years to 16 years of age according

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to the table; the lower line represents the rate of growth of a girl.

1. Explain how the points are located on the vertical lines so as to determine the curve.

2. In a similar way make curves on squared paper to represent the rate of increase in weight.

3. At what age does a girl attain her full height? Does a boy attain his earlier or later than this?

4. How do the lines show that a boy's height is always greater than a girl's?

5. Make similar comparisons in regard to weight.

6. During what period of years does the weight change most rapidly? The height?

7. In what period of years is the difference between weights and that between heights most marked?

8. If convenient, measure the heights of pupils and represent the results on squared paper.

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PROBLEMS-FOOD ECONOMY

Various foods furnish different amounts of nutriment, so that a food costing little may be of high value and vice versa. For example, 1 lb. of round beefsteak contains 51⁄2 oz. of nutriment, and a pound of stew beef 12 oz. The steak will cost about 144 a pound and the stew beef 54.

1. A pound of sirloin of beef costing 204 a pound furnishes 2.5 oz. of protein or nourishment, and 1 lb. of fresh codfish costing 10¢ furnishes 1.8 oz.; which is the cheaper food, sirloin or codfish?

The table shows the amounts of various foods that 104 will buy and the respective amounts of nourishment furnished:

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2. Which article of food furnishes the most protein for

the same cost? The most fat?

The most fat? The greatest number of

energy or heat units?

Make 10 other problems.

PROBLEMS-METEOROLOGY

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1. Claude let his toy balloon ascend by a string. A light breeze carried the balloon along at the rate of 2 mi. per hour. He followed the balloon for 40 minutes; how many miles did he walk?

2. A strong wind blowing 20 mi. per hour blew Mark's hat across a ravine. The hat was carried along a minute before it landed; how far was it carried in miles? In yards? In feet?

3. Charlotte sailed her boat in a breeze blowing 7 mi. per hour. The boat moved only as fast as the wind; how far did she sail in an hour? In 45 min. ?

4. From the dimensions given in the picture, find the area of the

6 FT.

4 FT.

8 FT.

-IN

sail of the boat. When a breeze of 7 miles per hour blows directly against a surface it exerts a pressure of .23 lb. per square foot. Find the total pressure on the sail of the boat.

5. Find the total area of the sails on this ship. When a strong wind exerts a pressure of 1.62 lb. per square foot, what is the total pressure on these sails?

6. A strong wind blows at the rate of 18 mi. per hour. If a schooner sailing in such a wind goes as fast as the wind, how many miles does it sail in 2 hours? 7. How long does it take a violent. gale blowing at the rate of 58 mi. an hour to cross Lake Michigan where it is 65 miles wide?

8. From Ludington to Milwaukee across Lake Michigan is 91 miles; how long would it take a gale blowing 45 mi. per hour to travel from Ludington to Milwaukee?

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PROBLEMS-METEOROLOGY

1. Find from the following table the pressure exerted on 2 sq. ft. of surface by each of the winds named.

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2. Find how many pounds pressure each wind would exert in blowing directly against the side of a house 50 ft. long and 18 ft. high.

3. A railroad engine is running directly against a high

wind.

If the surface exposed to the wind is 55 sq. ft., how many pounds pressure from the winddoes the engine overcome?

20 FT

14 FT.

4. The surface enclosed by dotted lines in the picture represents the area of the side of a haystack; how many square feet are there in this surface? How many pounds pressure would each kind of wind given in the table exert on the haystack in blowing directly against this surface? 5. A strong wind carries a balloon along for 51⁄2 hr. at 27 mi. per hr.; how many miles is the balloon carried?

16 FT.

6. A hurricane blowing 76 miles per hour tore a shingle from a house, carried it for 3 of an hour and dropped it at a distant village; how far from the house was the village?

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