We shall here conclude our observations on the mechanical powers. At our next meeting I shall endeavour to give you an explanation of the motion of the heavenly bodies.
Questions
31.(Pg. [62]) Describe a pulley, and its use.
32.(Pg. [62]) What is meant by a fixed pulley and why is not power gained by its employment? ([fig. 1. plate 5.])
33.(Pg. [62]) Of what use is the fixed pulley?
34.(Pg. [63]) How is the power gained by a moveable pulley, explained by means of [fig. 2. plate 5]?
35.(Pg. [63]) What proportion must the power bear to the weight in [fig. 2], that their momentums may be equal?
36.(Pg. [64]) What is a fundamental law as respects power and time?
37.(Pg. [64]) If to gain power we must lose time, what advantage do we derive from the mechanical powers?
38.(Pg. [64]) What name is given to two or more pulleys connected by one string?