Consider the system Figure 1 At a certain time the fluid in

Consider the system (Figure 1). At a certain time, the fluid in the system is applying a torque T = 31 N middot m on the shaft, which is not spinning. The environment is supplying a current I = 16 A through the resistor R = 140 Ohm. Pressure p_1 inside the chamber is 530 kPa. The piston is moving down at 2 m/s and there is no flow through the port at the top. What is the net power for the system? The area of the port is A_1 =10 cm^2 and the area of the piston is A_2= 295 cm^2.

Solution

The energy that is enter the system is T=31 N m + the electric energy= 16*140= 2240 W

and the exit energy is given by P1*Volume = P1*velocity*area= 530000x2x295/100^2 = 31270 W

so we do the exit - the enter =

31270-2240-31 = 28999 W of energy exit