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What power (in horsepower) is developed by a grinding machine whose wheel has a radius of 8.89 in and runs at 7.42 rev/s, when the tool to be sharpened is held against the wheel with a force of 47.3 lb

Respuesta :

Answer:

P = W / t     definition of power

P = F s / t = F v t / t = F v     power expended

v = 2 pi R f         f = frequency = rev / sec     (S = 2 pi R n = 2 pi R f t)

                                                                        and v = S / t

P = F 2 pi R f = 47.3 lb * 6.28 * .741 ft * 7.42 / sec = 1630 ft-lb/sec

(1630 ft-lb/sec) / (550 ft-lb/sec / HP) = 2.96 HP  

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