Physics, 27.02.2020 03:51, rainbow7020
Circular copper rods of diameter D= 1.75 mm and length L= 25 mm are used to enhance heat transfer from a surface that is maintained at Ts,1= 100°C. One end of the rod is attached to this surface (at x= 0), while the other end (x= 25 mm) is joined to a second surface, which is maintained at Ts,2= 0°C. Air flowing between the surfaces (and over the rods) is also at a temperature of [infinity] T[infinity]= 0°C, and a convection coefficient of h= 125 W/m2·K is maintained. (1) What is the rate of heat transfer by convection from a single copper rod to the air, in W? (2) What is the total rate of heat transfer from a 1 m × 1 m section of the surface at 100°C, if a bundle of the rods is installed on 4-mm centers, in W?
Answers: 3
Physics, 21.06.2019 23:30, Longjeremiahs8864
1.in one challenge on the titan games, competitors have to lift 200 pounds up a long ramp. angel is able to move the weight in 42 seconds. anthony gets it done in only 38 seconds. which statement is true? angel has more power than anthony. angel does more work than anthony. anthony does more work than angel. anthony has more power than angel. 2.a mountain climber exerts 41,000 j of work to climb a cliff. how much power does the climber need if she wants to finish in only 500 seconds? power = work / time 20,500,000 watts 82 watts 0.0122 watts 41,500 watts 3.your family is moving to a new apartment. while lifting a box 83 joules of work is done to put the box on a truck, you exert an upward force of 75 n for 3 s. how much power is required to do this? (hint: you only need two of the 3 numbers given! ) power = work / time 249 watts 25 watts 2075 watts 27.7 watts
Answers: 1
Physics, 22.06.2019 06:30, bluevibe
2kg of refrigerant 134a undergoes a polytropic process in a piston-cylinder assembly from an initial state of saturated vapor at 2 bar to a final state of 12 bar, 80 degree c. a)determine the work for the process in kj. b)sketch the process on a p-v diagram.
Answers: 2
Circular copper rods of diameter D= 1.75 mm and length L= 25 mm are used to enhance heat transfer fr...
Mathematics, 18.04.2020 04:56