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3.1.1 )

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Bar diameter d_b = 50 mm

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d_r = 50/1000 = 0.05 m

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r = d/2 = 0.05/2 = 0.025 m

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Torque required to overcome friction of the lathe spindle T_f = 12 N-m

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Tangential force F = 2400 N

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Torque T = rF

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T = (0.025)(2400)

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T = 60 N-m

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Torque required at the driving pulley on the machine is 60 N-m

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