2. A 70 kg hiker climbed a mountain 1000 m high. He reached the peak in 3 hr. A. Calculate the external work done by the climber. B. Assuming the work was done at a steady rate during the 3 hr period. Calculate the power generated during the climb. C. Assuming the average O2 consumption during he climb was 2 liters/min (corresponding to 9.6 kcal/min), find the efficiency of the hiker's body. D. How much energy appeared as heat in the body?

2. A 70 kg hiker climbed a mountain 1000 m high. He reached the peak in 3 hr. A. Calculate the external work done by the climber. B. Assuming the work was done at a steady rate during the 3 hr period. Calculate the power generated during the climb. C. Assuming the average O2 consumption during he climb was 2 liters/min (corresponding to 9.6 kcal/min), find the efficiency of the hiker's body. D. How much energy appeared as heat in the body?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

1. A gas releases 35 J of heat as 84 J of work was done to compress it. Calculate the change in energy. 2. What is the work done by a system when it absorbs 47 J of heat and gain 12 J of energy? 3. How much heat is released by a system when 45 J of work is done on it to decrease its energy to 23 J? 4. Suppose a woman does 500 J of work and 9500 J of heat transfer occurs into the environment in the process. What is the decrease in her internal energy, assuming no consumption of food? 5. A thermodynamic system undergoes a process in which its internal energy decreases by 500 J. If at the same time 220 J of work is done on the system, find the thermal energy transferred to or from it.
QI. A hydroelectric station has a cubic tank of height 50m above the earth. This cubic tank has an equal part of 35m. The maximum height of water in the tank is 25m for one day and the minimum height of water in the tank is 5m for one day also. The efficiency of the station is 0.9. Find 1. The power that developed by the station. 2. The maximum power that developed by the station. 3. The maximum power that could be developed by the : 35m 25m 5m Som earth COOL
A car having a mass of 1200 kg accelerates from 30 to 70 km/h on an uphill road. The car travels 200 meters during the acceleration and the slope of the road from horizontal is 25°. Perform the following analysis: a. Find the change in kinetic energy of the car in kJ. b. Find the change in potential energy of the car in kJ. c. Find the work done by the engine in kJ. (Neglect losses such as those due to friction)
2) The energy consumed by a shower for 30 days is 22kwh. It is known that the resistance of the showerhead is 20 ohms and that its nominal current is 15A. So, what is the time in minutes that the shower was turned on during this period?
2- Water vapor at a flow rate of 20000 kg / hour enters a steam boiler with a specific volume of 150 kPa 0.001053 m3 / kg. With the energy it takes from the fuel in the combustion chamber of the boiler, it rises at 150˚C at 1200 kPa. If the boiler is badly insulated and loses 500 kW of heat to the environment, calculate the time required to increase 1 ton of water to 150 ° C in the boiler. A. 660 sB. 445 sC. 330 sD. 1330 sE. 1666 s
1. A rigid tank contains a hot fluid that is cooled while being stirred by a paddle wheel. Initially, the internal energy of the fluid is 800 kJ. During the cooling process, the fluid loses 500 kJ of heat, and the paddle wheel does 100 kJ of work on the fluid. Determine the final internal energy of the fluid. Neglect the energy stored in the paddle wheel.
3. A heat engine operating between a geothermal steam source at 205°C and a riv- er at 18°C achieves an efficiency of 22%. What percentage of its theoretical max- imum efficiency is it achieving?
15. Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. During the process, 30 kJ of heat is transferred to the water, and 5 kJ of heat is lost to the surrounding air. The paddle wheel work amounts to 500 N-m. Determine the final energy of the system if its initial energy is 10 kJ.
2. What is the work done by a system when it absorbs 47 J of heat and gain 12 J of energy? 3. How much heat is released by a system when 45 J of work is done on it to decrease its energy to 23 J? 4. Suppose a woman does 500 J of work and 9500 J of heat transfer occurs into the environment in the process. What is the decrease in her internal energy, assuming no consumption of food? 5. A thermodynamic system undergoes a process in which its internal energy decreases by 500 J. If at the same time 220 J of work is done on the system, find the thermal energy transferred to or from it.
1. Steam enters a system with an enthalpy of 1292 Btu/lb and leaves with an enthalpy 158 Btu/lb less than when it entered. Assume that there is a 9-ft change in elevation and a 13 Btu/lb amount of heat is transferred to the environment during the process. What is the work in Btu/min and in hp for a flow of 0.91 kg/s.
Q1/ The air circulation in a large room by using fan (10 hp). Assuming a well-insulated, sealed room determine the internal energy increase after (1 h) of operation.
1. Calculate the kinetic energy of a body that has a mass of 5 kg and velocity of 10 m/s.2. In a non-flow process carried out 5.4 kg substance, there was a specified internal energy decrease of50 kJ/kg and a work transfer of the substance of 8.5 kJ/kg. Determine the heat transfer and a statewhether it is gain or loss.3. A gas is contained in a cylinder with a moveable piston on which a heavy block is placed. Suppose theregion outside the chamber is evacuated and the total mass of the block and the movable piston is102 kg. When 2140 J of heat flows into the gas, the internal energy of the gas increases by 1580 J.what is the distance through which the piston rises?4. Calculate the increase in internal energy of a gas in a closed system during a process in which 100 Jof heat is supplied to the system and 400 J of work is produce.5. Convert the following readings of pressure to kPa, assuming the barometer reads 760 mm Hg. a. 90 cm Hg gaugeb. 40 cm Hg vacuumc. 1.2 m H20 gauge 6. A creature…