1.Helium(15 degrees Celsius, 1atm) will be transported in a straight horizontal copper tube over a distance of 150 m at a rate of 0.1 m^3/s. If the pressure drop in the tube should exceed 6 in h20, what is the minimum pipe diameter? ( first classify the problem as case 1, 2 , or 3)
2.The electrical power supplied to the motor is 90 kW. The motor in turn delivers 100 hp at a speed of 1000 rpm to a hoist arrangement for an elevator. Define the electric motor as the system and calculate the rate of work for the system.
3.A low consumption solar refrigerator uses 12-v d.c. battery for the supply of 60 W of electrical power to the motor that drives the compressor of the refrigeration device. What is the current supplied to the motor?
4.A 45 W electric mixer is operated for 5 minutes while mixing a 2 kg shake. Assume Csubv=4200 J/kg-K for the liquid. Determine the temperature rise (in degrees C) of the milk shake.