Um motor de indução trifásico de 220 V é conectado a rede elétrica por meio de um circuito trifásico com cabos de resistência total 0,25Ω. A corrente de regime desse motor é igual a 8 A. Se a corrente para partida direta for igual a 8 vezes o valor da corrente de regime, utilizando-se o método de partida estrela-triângulo qual será a tensão nos terminais desse motor na partida? A) 216,7 V
B) 204,8 V
C) 214,7 V
D) 218,3V
E) 220V constante porque é a tensão da rede.

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

Acertain flow of air (at stp) has a velocity distribution given by v i (in ft/s). if this flow is going through a 4 ft square area in the yz-plane (centered at the origin), what is the mass flow rate (in lbm/s)?

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false