question_answer

The following data refers to an open belt drive:

	Pulley A	Pulley B
Purpose?.	Driving	Driving
Diameter?.	450  mm	750 mm
Angle of contact?.	\[{{\theta }_{A}}\,=\,150\]	\[{{\theta }_{B}}\,=\,210{}^\circ \]
Coefficient of friction between belt and pulley	\[{{f}_{A}}\,=\,0.36\]	\[{{f}_{B}}\,=\,0.22\]

The ratio of tensions may be calculated using the Relation \[({{T}_{1}}/{{T}_{2}})\,=\]exp (z) where z is:

A) \[{{f}_{A}}{{\theta }_{A}}\]                            

B) \[{{f}_{B}}{{\theta }_{B}}\]

C) \[({{f}_{A}}+{{f}_{B}})\,({{\theta }_{A}}+{{\theta }_{B}})/4\]           

D) \[({{f}_{A}}{{\theta }_{A}}+{{f}_{B}}{{\theta }_{B}})/2\]