Cubic measure is used in measuring the volume of solids. Table of Solid or Cubic Measure 1,728 cubic inches = 1 cubic foot. 27 cubic feet 1 cu. yd. The measure of volume for liquids. Table of Liquid Measure Liquids are sometimes measured with cubic measure, the U. S. gal. contains 231 cu. in. so that a cu. ft. of water contains approximately 7 gallons. One gallon of water taken at the temperature of maximum density, 39.1° F., weighs 8.3389 lbs., avoirdupois, which is approximately 83 lbs. A cubic foot of water weighs 62.355 lbs., approximately 62 lbs. Water freezes at 32° F. or 0° C., and boils at 212° F (Fahrenheit) or 100° C. (Centigrade). The standard unit for weight in shop practice is the avoirdupois pound. Time is the measure of duration. Table of Measure for Time Angular measure is used in measuring angles. 60 seconds (60′′) = 1 minute (1'). 60 minutes (60') = 1 degree (1°). 360 degrees (360°) = 1 circumference. Money is the measure for values. It is used as a medium 1 eagle $10=100 dimes = 1,000 cents 10,000 mills. = Weights of Materials 1 cu. in. of cast iron 1 cu. in. of copper 1 cu. in. of brass 1 cu. in. of lead 65 weighs .2604 lb. melts at 2,500° F. weighs 2779 lb. melts at 3,100° F. weighs .2833 lb. melts at 3,000° F. weighs .3195 lb. melts at 1,930° F. cop: 95 weighs.3029 lb. melts at 1 cu. in. of aluminum weighs .4106 lb. melts at 625° F. weighs .0963 lb. melts at 1,160° F. The approximate weight of round bar iron or steel can be found by the formula L: (dx4)2 where L= weight of one foot in length of the bar and d = diameter of the bar in inches. Horse Power The horse power is an expression for foot-pounds of useful work accomplished in a specified time. 1 H. P.=33,000 pounds raised 1 foot in one minute, or 1 pound raised 33,000 feet in one minute. Electric Units The volt is the unit of electrical pressure. The ampere is the unit of current strength or rate of flow. The ohm is the unit of resistance. The watt is the unit of power. The ohm, ampere and volt are defined in terms of one another as follows: Ohm, the resistance of a conductor through which a current of one ampere will pass when the electro-motive force is one volt. Ampere, the quantity of current which will flow through a resistance of one ohm when the electro-motive force is one volt. Volt, the electro-motive force required to cause a current of one ampere to flow through a resistance of one ohm. The relation which these quantities bear to one another is expressed by Ohm's Law. where R E the electro-motive force in volts, C=current in amperes. The electric H. P.-746 watts. METRIC SYSTEM OF MEASURES The metric system is used in almost all the European countries and is authorized by law in the United States and is in general use for all scientific treatises. Metric Linear Measure 10 millimeters (mm.) = 1 centimeter (cm.). 10 centimeters 10 decimeters 10 meters 10 dekameters 10 kilometers = = = 1 decimeter (dm.). - 1 meter (m.). = 1 myriameter (Mm.). 1 Mm. = 10 Km. = 100 Hm. = 1,000 Dm. = 10,000 meters. 1 m.=10 dm.=100 cm. =1,000 mm. =39.37 inches. The unit for metric linear measure is the meter. Metric Square Measure 100 sq. millimeters = 1 sq. centimeter (sq. cm.). = = 1 sq. dekameter (sq. Dm.). 100 sq. dekameters = 1 sq. hektometer (sq. Hm.). 100 sq. hektometers = 1 sq. kilometer (sq. Km.). The unit for metric square measure is the square meter for small surfaces, and the are for land measurements. 100 centares = 1 are 1 sq. meter=1.196 sq. yard 100 ares= 1 hectare = Metric Cubic Measure 1,000 cu. millimeters = 1 cu. centimeter (cu. cm.). 1,000 cu. centimeters = 1 cu. decimeter (cu. dm.). 1,000 cu. decimeters == The unit for cubic measure is the cubic meter and 1 cu. m. 1.308 cu. yard. 10 liters = = 1 dekaliter (Dl.). 10 dekaliters =1 hektoliter (Hl.). 10 hektoliters = 1 kiloliter (Kl.). The unit for capacity for both liquid and dry measure is the liter. 1 liter = .908 of a dry quart. 1 liter = 1.0567 of a liquid quart. |