Question

Which of the following expression represent the angular acceleration α of the connecting rod?

(a) −ω^2 . sin θ/n

(b) −ω^2 . cos θ.n

(c) ω^2. cos θ/n

(d) ω^2 . sin θ.n

I got this question in unit test.

I would like to ask this question from Angular Velocity and Acceleration of the Connecting Rod in division Inertia Forces in Reciprocating Parts of Machine Dynamics

Answer 1

The correct answer is (a) −ω^2 . sin θ/n

To explain I would say: Angular acceleration is the rate of change of angular velocity, for the connecting rod it depends on the length of the rod and crank’s radius. The negative signs indicate that the sense of rotation tends to reduce the angle phi.