In Fig. 9.74, two free-body diagrams are shown of a single-cylinder engine in which the rotating masses are counterbalanced. Figure 9.74.a is a free-body diagram of the moving parts of the slider crank, and Fig. 9.74b is a free-body diagram of the engine block together with the slider crank. Show vectors of the forces and torques acting on the free bodies when the engine operates at constant crank speed and is under gas pressure during the power stroke. Explain each vector.
