13. If a locomotive has an efficiency of 6 per cent. and develops 1700 horse-power how much coal is burned in an hour?
14. If an automobile engine burns 1 gallon of gasoline in an hour and develops 10 horse-power, what is its efficiency?
15. The A.L.A.M.[J] formula for horse-power is (N B2)/2.5 when the piston speed is 1000 ft. per minute, N being the number of cylinders and B, their diameter. Find the horse-power of a 4-cylinder engine, the cylinders having a diameter of 4 in.
16. Find the horse-power of a 6-cylinder automobile engine, if the cylinder diameter is 4.5 in.
17. A 4-cylinder automobile having 4-in. cylinders, uses 1 gallon of gasoline in 1 hour. Find its efficiency, if its average horse-power developed is 6.
18. The motor boat Disturber III, has 24 cylinders each with diameter 3.5 in. If the piston speed is 1000 ft. per minute, what is the horse-power? (See problem 15.)
Review Outline: Heat
Heat; sources (4), effects (5), units (2).
Temperature; thermometer scales (3), absolute temperature, 9C°/5 + 32° = F°.
Expansion; gases, Law of Charles (V1/V2 = T1/T2), liquids, peculiarity of water, solids, coefficient of expansion, uses, results.