1. A wrench is being used at an angle 20° from the perpendicular. Explain why the angle 70° is used in the equation when calculating torque.

Many machines- including inclined planes such as ramps- increase the strength of the force put into the machine but decrease the distance over which the force is applied.

Which process is represented by the pv diagram? a. the isobaric process b. the isovolumetric process c. the isothermal process d. the adiabatic process

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.