Meriam, Kraige & Bolton — Plane Kinetics of Rigid Bodies: Problem 6_86

6/86 The connecting rod $AB$ of a certain internal-combustion engine weighs $1.2\text{ lb}$ with mass center at $G$ and has a radius of gyration about $G$ of $1.12\text{ in.}$ The piston and piston pin $A$ together weigh $1.80\text{ lb}$. The engine is running at a constant speed of $3000\text{ rev/min}$, so that the angular velocity of the crank is $3000(2\pi)/60 = 100\pi\text{ rad/sec}$. Neglect the weights of the components and the force exerted by the gas in the cylinder compared with the dynamic forces generated and calculate the magnitude of the force on the piston pin $A$ for the crank angle $\theta = 90^\circ$. (Suggestion: Use the alternative moment relation, Eq. 6/3, with $B$ as the moment center.)