Question

If OC is the crank and PC is the connecting rod of a reciprocating steam engine and rotates with uniform angular velocity in clockwise direction in the given figure below: then under which condition the piston will undergo retardation?

(a) N lies to the right of O

(b) N lies to the left of O

(c) N is above O

(d) N is below O

I had been asked this question during an interview.

This interesting question is from Klien’s Construction topic in division Inertia Forces in Reciprocating Parts of Machine Dynamics

Answer 1

Correct option is (a) N lies to the right of O

For explanation: The point N has to remain in the horizontal line of OP thus both the options of N being above O and N being below are incorrect. When N lies to the left of O the piston undergoes acceleration.