$13-20$

For the given slider$-$crank mechanism,

a$)$ Calculate the inertia force for the unbalanced mechanism.

b$)$ Exactly balance the crank and recalculate the inertia force.

c$)$ Overbalance the crank with a counter weight of mass equal to the sum of mass at the crank pin and two$-$thirds of mass at the wrist pin. The counter weight is placed opposite to the crank at a radius r $.$ Recalculate the inertia force after overbalancing.

d$)$ Compare results from $($b$)$ and $($c$)$ with result from $($a$)$ for the unbalanced mechanism.

Crank: $m_2=0\mathrm{.}05$ blob; Connecting rod: $m_3=0\mathrm{.}02$ blob; Piston: $m_4=0\mathrm{.}019$ blob

Crank angular velocity: $=3000rpm$ : Crank angle: $=30$

Answer in lbf