The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity $${\omega _1}$$ rad/s in the clockwise direction and the link OB turns with angular velocity $${\omega _2}$$ rad/s in the anticlockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)
A. $${\omega _1}{\omega _2}{\text{r}}$$
B. $$\left( {{\omega _1} - {\omega _2}} \right){\text{r}}$$
C. $$\left( {{\omega _1} + {\omega _2}} \right){\text{r}}$$
D. $$\left( {{\omega _1} - {\omega _2}} \right)2{\text{r}}$$
Answer: Option C
This Question Belongs to Mechanical Engineering >> Theory Of Machine
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Comments ( 1 )
In considering friction of a V-thread, the virtual coefficient of friction (μ1) is given by
A. μ1 = μsinβ
B. μ1 = μcosβ
C. $${\mu _1} = \frac{\mu }{{\sin \beta }}$$
D. $${\mu _1} = \frac{\mu }{{\cos \beta }}$$
The lower pairs are _________ pairs.
A. Self-closed
B. Force-closed
C. Friction closed
D. None of these
In a coupling rod of a locomotive, each of the four pairs is a ________ pair.
A. Sliding
B. Turning
C. Rolling
D. Screw
A kinematic chain is known as a mechanism when
A. None of the links is fixed
B. One of the links is fixed
C. Two of the links are fixed
D. None of these
=> B. is the correct answer. [not C]
exp,
link 1 - cw(+ve) omega1
link 2 - acw(-ve) omega2
r = radius of pin
so, we know that
Vr = r (omega1 - omega2) # {Vr - rubbing velocity}
Vr = r ( omega12 )