A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is $$\alpha $$. The effort applied parallel to the plane is given by (where $$\mu $$ = $$\tan \varphi $$ = Coefficient of friction between the plane and the body)
A. $${\text{P}} = {\text{W}}\tan \alpha $$
B. $${\text{P}} = {\text{W}}\tan \left( {\alpha + \varphi } \right)$$
C. $${\text{P}} = {\text{W}}\left( {\sin \alpha + \mu \cos \alpha } \right)$$
D. $${\text{P}} = {\text{W}}\left( {\cos \alpha + \mu \sin \alpha } \right)$$
Answer: Option C
This Question Belongs to Mechanical Engineering >> Theory Of Machine
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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
Effort applied = P (acting to the right).
Frictional force = uWcosa(acting against P).
Gravitational force = Wsina(acting downwards).
So equation will be in equilibrium as:
P = Wsina + uWcosa.
P = W(sina+ ucosa).
the answer should be P = W(sin alpha + mu cos alpha) / ( cos alpha - mu sin alpha )