Question

For an inline slider-crank mechanism, the lengths of the crank and connecting rod are 3 m and 4 m respectively. At the instant when the connecting rod is perpendicular to the crank, if the velocity of the slider is 1 m/s, the magnitude of angular velocity (upto 3 decimal points accuracy) of the crank is _________ radian/s.

Answer 1

The magnitude of angular velocity of the crank is 0.266 r

Sin Ф = 3/5

Cos Ф = 4/5

Velocity of slider = Vb = 1m/s

According to the velocity figure approach -

ΔOAP is similar to ΔOAB

Vb/OP = Va/OA = Vba/ AP = ω --- eq 1

OP = 5 + tanФ

= 5 (3/4)

Now, from equation 1 -

ω = 4 / 5 × 3

= 4/15

= 0.266 rad