)(si units) a shielded metal arc-welding operation is performed on low-carbon steel plates at a voltage = 25 volts and current = 150 amps. the heat transfer factor = 0.90, and the melting factor = 0.75. the melting temperature of low-carbon steel = 1487°c, and the unit melting energy can be determined by the methods of the previous chapter. using si units, determine the (a) rate of heat generation at the weld and (b) volume rate of metal welded.

Wo small variable-thrust jets are actuated to keep the spacecraft angular velocity about the z-axis constant at ? 0 = 1.16 rad/s as the two telescoping booms are extended from r1 = 1.18 m to r2 = 4.69 m at a constant rate over a period of 124 seconds. the small 19-kg experiment modules at the ends of the booms may be treated as particles, and the mass of the rigid booms is negligible. determine the necessary thrust t for each jet as a function of time where t = 0 is the time when the telescoping action is begun. after you have the general expression for t, answer the questions. show work.