When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the ________ pulley must be taken into consideration.

A. μ₁ = μsinβ B. μ₁ = μcosβ C. $${\mu _1} = \frac{\mu }{{\sin \beta }}$$ D. $${\mu _1} = \frac{\mu }{{\cos \beta }}$$

A. Self-closed B. Force-closed C. Friction closed D. None of these

A. Sliding B. Turning C. Rolling D. Screw

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