REVIEW QUESTIONS

ON THE SUBJECT OF

MECHANICS.

EXERCISE I.

1. Define (a) molecule, (b) atom.

2. What are the three forms in which matter may exist?

3. Distinguish between a gas and a liquid.

4. (a) Name the universal properties of matter, and (b) what is a characteristic property of matter?

5. What is meant by tenacity?

6. What is meant by inertia?
7. What is porosity?

EXERCISE II.

1. Define (a) motion, (b) velocity.

2. Distinguish between uniform and variable velocity.

3. A rolling ball has a uniform velocity. It travels 2,400 feet in 8 minutes. What is its velocity in feet per second?

same.

Ans. 5 feet per second. 4. Define variable velocity, and give an example of the

EXERCISE III.

1. Give a definition of force.

three things must be considered?

In treating of forces what

2. What does the momentum of a body measure or signify?

1. Why does water cling to the hand when it is dipped? 2. What is adhesion?

3. Is capillary attraction a result of cohesion or of adhesion? 4. What substance with which you are familiar exerts strong capillarity?

5. What is cohesion?

6. How may we entirely destroy the cohesion of a liquid?

EXERCISE II.

1. (a) When is a body stressed? (b) What is the difference between tensile and compressive stress?

2. (a) Define unit stress. (b) Unit deformation.

3.

What is the unit elongation per foot of a block six feet long if the total elongation is .012 inch? Ans. .002 inch.

4. State as fully as you can the action of a piece of iron that is loaded beyond its elastic limit.

5. (a) Define ultimate breaking strength. (b) Permanent set. (c) What can you say of the elasticity of a body which is subjected to a small stress?

6. What is the relation of the deformation of a body under small stress to its length?

7. What is the ultimate tensile strength of steel?

8. Find the coefficient of elasticity of a substance, if the unit stress is 48,000 pounds and the unit deformation is .0016. Ans. 30,000,000.

9. Find the area of a square wrought-iron bar that will just stand a tensile stress of fifty-five tons. The breaking stress is 50,000 pounds per square inch. Ans. 2 square inches.

10. What is the elongation of a bar 18 inches square and 24 feet long, under a tensile stress of 9,000 pounds, if the unit elongation is .007 inch?

11. A bar of steel is

Ans. .168 inch.

inch in diameter and 6 inches long.

If it breaks under a load of 45,000 pounds, what is the unit breaking strength?

Ans. 75,000 pounds (about).

REVIEW QUESTIONS

ON THE SUBJECT OF

НЕАТ.

EXERCISE I.

1. A body has a temperature of 512° F.; what do you know with regard to the amount of heat the body possesses?

2. Give as good a definition as you can in your own words of the term "cold."

3. How is the zero point of the Fahrenheit thermometer determined?

4. Express a temperature of 64° F. in Centigrade degrees. Ans. -531° C.

5. How many degrees F. would a temperature of —45° C. indicate?

6. Give an example of linear expansion from your own observation.

7. At what temperature in degrees Centigrade and Fahrenheit is water at its maximum density?

8. Find the length of a wrought-iron piston-rod when it has been heated to 140° F. Its length at 40° F. is 6 feet.

Ans. 6.003888 feet.

EXERCISE II.

1.

Find the volume of 720 liters of air at 37° C., when heated to 90° C. Ans. 843 liters (approx.).

2. A cylinder holds 12 cubic feet of CO2 gas at 100° C., and for every cubic foot of expansion the pressure is increased 4 pounds. What must be the increase of pressure if the gas is heated to 110° C.? Ans. 1.2 pounds.