174. What is said of the velocities of the heavenly bodies?
CHAPTER XI.
174. What are the Mechanical Powers? Why is the term power not strictly proper?
175. Explain the terms power, weight, and fulcrum. What is said of the use of the lever? What is the lever of the first kind? What is said of its force?
176. What is said of scales? What of steelyards?
177. Give examples of the first kind of lever. Show by Fig. 159 that there is no gain of power in this lever.
178. Give the illustration of the see-saw. What is said of Archimedes's lever?
179. State the analogy between this lever and the Hydrostatic Bellows, Bramah's Press, etc. What is the lever of the second kind? Apply the rule of equilibrium to it. Show how the common wheel-barrow is a lever of this kind.
180. Give other examples of the second kind of lever. What is lever of the third kind? How does this differ from the other two kinds? Apply the rule of equilibrium to it.
181. Give examples of the third kind of lever. Show how it acts at a mechanical disadvantage in the different examples mentioned. State in full what is said of muscular action.