The pressure exerted by water on the surface of the culvert must be determined. The pressure exerted by water on the surface of the submarine is to be determined. The effect of the spring force in the range of 0 to 500 N on the pressure inside the cylinder must be investigated.
The specific gravity of one liquid is known, and the specific gravity of the other liquid must be determined. The diameter of the piston on which the weight is to be placed must be determined. The effect of the number of people carried in the balloon on acceleration should be investigated.
The pressure difference between the top and bottom of the vessel must be determined. Patm= 92 kPa h Analysis The pressure at the bottom of the pipe can be expressed as. For a given vertical level difference, the excess pressure in the channel and the length of the differential liquid column must be determined.
For a given pressure gauge reading, the gauge pressure of the gasoline line must be determined.
ENERGY, ENERGY TRANSFER, AND GENERAL ENERGY ANALYSIS
The average velocity of the air and the conversion efficiency of the turbine must be determined. Discussion Note that about one-third of the wind's kinetic energy is converted into energy by the wind turbine, which is typical for real turbines. The overall efficiency of the unit and the pressure difference between the inlet and the outlet of the pump must be determined.
The change in mechanical energy of the water as it flows through the pump consists only of the change in flow energy because the height difference across the pump and the change in kinetic energy are negligible. Discussion Note that only two-thirds of the electrical energy consumed by the pump motor is converted into mechanical energy of the water; the remaining third is lost due to pump and motor inefficiencies. Therefore, the power potential of the wind is its kinetic energy, which is V2/2 per unit mass.
Analysis To determine the mechanical efficiency of the pump, we need to know the increase in the mechanical energy of the fluid as it flows through the pump, which is. Discussion The overall efficiency of this pump will be lower than 83.8% due to the inefficiency of the electric motor driving the pump. Analysis Then the total mechanical energy of a fluid is the sum of the potential, flow and kinetic energy, and is expressed per unit mass as.
To determine the mechanical efficiency of the pump, we need to know the increase in mechanical energy of the fluid as it flows through the pump. Discussion The total efficiency of this pump/motor unit is the product of the mechanical efficiency and the motor efficiency. 2 The difference in height between the lake and the free surface of the basin is constant.
But excessive amounts of these gases upset the delicate balance by trapping too much energy, causing the Earth's average temperature to rise and the climate in some locations to change. These unwanted consequences of the greenhouse effect are referred to as global warming or global climate change. 2-93C Emissivity is the ratio of the radiation emitted by a surface to the radiation emitted by a black body at the same temperature.
Steady operating conditions exist since the surface temperatures of the wall remain constant at the specified values. 2
2 The thermal properties of the ball and the convection heat transfer coefficient are constant and uniform. Using EES (or any other) software, investigate the effect of the convection heat transfer coefficient and the surface emissivity on the heat transfer rate from the ball. The temperature of the iron base should be determined in steady operation.
2 The thermal properties of the iron base and the convection heat transfer coefficient are constant and uniform. Analysis When the heat loss of the plate by convection is equal to the solar radiation absorbed, the surface temperature of the plate can be determined from. Using EES (or other) software, investigate the effect of the convection heat transfer coefficient on the surface temperature of the plate.
The spacecraft surface temperature must be determined when steady state conditions are reached. Analysis When the heat loss from the outer surface of the spacecraft by radiation corresponds to the absorbed solar radiation, the surface temperature can be determined from. 4 The inner surface of the shell has the same temperature as the ice water, 0°C.
The power produced, the blade tip speed and the revenue generated by the wind turbine per year must be determined. Then the power consumption costs of the pump, the income generated by the turbine and the net income (revenue minus costs) per year. Both tanks are open to the atmosphere and the height difference between the free surfaces of the tanks is 30 meters.
The pressure difference between the outlet and inlet of the pump at full load is measured to be 211 kPa. If the convection heat transfer coefficient on the surface of the board is 10 W/m2.°C and the radiation heat transfer is negligible, the average chip surface temperature is. The surface temperature of the wire is measured to be 130°C when a wattmeter indicates that the electricity consumption is 4.1 kW.
PROPERTIES OF PURE SUBSTANCES
The temperature value on the process curve on the P-v diagram should be placed. For this set of data, the temperature values in states 1 and 2 should be placed on its axis. Now the valve opens and half the gas mass can escape.
If the final pressure in the tank is 2.2 atm, the final temperature in the tank is Solutions can be verified by copying and pasting the following lines into a blank EES screen. -136 The pressure of an automobile tire is measured to be 190 kPa (gage) before a trip and 215 kPa (gage) after the trip in a place where the atmospheric pressure is 95 kPa.
If the air temperature in the tire before the trip is 25°C, the air temperature after the trip is -138 Water is boiled at 1 atm pressure in a coffee maker equipped with an immersion-type electric heating element. After the brewing started, it is observed that half of the water in the coffee maker evaporated in 18 minutes.
If the heat loss of the coffee maker is negligible, the power rating of the heating element is. Now a leak occurs, and the pressure in the can drops to the local atmospheric pressure of 90 kPa. The temperature of the coolant in the can is expected to drop to (rounded to the nearest whole number).
ENERGY ANALYSIS OF CLOSED SYSTEMS
The final temperature and the boundary work must be determined for the isentropic expansion of nitrogen. Properties Note that the pressure remains constant during this process, the specific volumes are at the initial and the final conditions (Tables A-4 to A-6). Properties Note that the pressure remains constant during this process, the specific volumes are at the initial and the final conditions (Tables A-11 to A-13).
The effect of pressure on the work performed as the pressure varies from 400 kPa to 1200 kPa must be investigated. Properties Note that the pressure remains constant during this process, the specific volumes are at the initial and the final conditions (Tables A-4E to A-6E). The boundary work done during this process must be determined by drawing the process on a P-V diagram and also by integration.
The marginal work during this process is simply the area under the process curve, which is a trapezoid. The process described in the problem must be plotted on a P-V diagram and the effect of the polytropic exponent n on the boundary work as the polytropic exponent varies from 1.1 to 1.6 must be plotted. This function is required since the expression for boundary work depends on whether n=1 or n<>1".
Properties The gas constant for nitrogen is R = 0.2968 kJ/kg.K (Table A-2a) Analysis The boundary work for this polytropic process can be. The unit of the quantity 10 and the boundary work done during this process must be determined. Using the integration function, the work done must be calculated and compared, and the process plotted on a P-V diagram.
The final pressure, the boundary work done by the gas, and the work done against the spring must be determined and a P-V diagram drawn. The final pressure and temperature and the limit work done should be determined and the process should be shown on a P-V diagram. Then the marginal work during this process is simply the total area under the process curve.
