A Manual of Mechanics

THIS little work is evidently meant for readers whose knowledge of mathematics is small. The amount of mathematical knowledge supposed may, perhaps, be best inferred from an example quoted from the book itself. In p. 32 we have the problem to find the resultant of two equal rectangular forces, P. If ft is the resultant, R = P√2. “Now √2 = √50/25 = √49/25 very nearly;..√2 = 7/5 Very nearly. Whence R = 7/5 P.” When the angle between the lines of action of the forces is 120°, R should be equal to P; but it is proved in p. 33 to be equal to P √3, by an unaccountable error in the application of an elementary formula. However, √3 is found by the same process as before. Thus √3 = √48/16 = √49/16, very nearly, = 7/4.A Manual of Mechanics; an Elementary Text-Book, designed for Students of Applied Mechanics.By T. M. Goodeve (London: Longmans, 1886.)