HVAC-Questions

A 60 W light bulb is switched on for 18 hours per day. Assuming the power company charges 10 cents for each kilowatt-hour of electricity used, estimate the cost to operate the bulb for 30 days. S0.8 O b. S2.52 S2.9 c. O d. S1.8 S3.24 Oe.

2.1 A university campus has 30 classrooms and 300 offices. In each classroom, there are 16 fluorescent tubes that use 110 W of electrical power per fluorescent tube. The offices have two fluorescent tubes each, 110 W per fluorescent tube. The university is open 280 days a year. The classrooms and offices are not used for 6 hours per day, but the light is on all day. Assume that the electricity price is NOK 1.5/kWh. How much does the university save each year if all the lights are tumed off for the 6 hours, not even the classrooms or the offices are used? 2.2 Water is pumped from a lake to a large storage tank which is open to the atmosphere at the top. The water surface in the storage tank is 20 m above the water surface of the lake. The volume flow is 40 litres/s and 11.5 kW of electrical power is used to pump the water from the lake to the storage tank. Disregard losses in flow energy due to friction and from changes in the kinetic energy of the water. Use y=998 kg/m3 as the mass…

Q1) A wind turbine generates 1576800 kWh in a year. The generated electricity is sold to the utility at a rate of 0.05$/kWh. The discount rate is 5%. Calculate the present value of electricity generated by the turbine throughout its life period of 20 years.

Demand factor is 0.75 on a Distributing Transformer that supplies a group of general power customers having a connected load of 186 kW. If the load factor for the group will average 45% and the energy sells at 3.5 cents per kWh, what will be the monthly (30-day) income from energy delivered through this transformer in Php/month; assuming an average motor efficiency to be 75%. (12) O 1,106.14 998.25 O 1,406.16 O 1,298.78 O 1,034.31

When a stationary mass of gas was compressed without friction at constant pressure its initial state of 0.8 m3 and 0.105 MPa was found to change to final state of 0.40 m3 and 0.105 MPa. There was a transfer of 85 kJ of heat from the gas during the process.How much did the internal energy of the gas change ? * 1 Add File

How do you determine how much it will cost for electricity per year for the Nissan Leaf

1.5. A refrigerator is used to cool 4 litres of soft drink from room temperature (25 °C) to 3 °C. If the density of the soft drink is 1015 kg/m3 (1 litre = 0.001 m³), how much heat must be removed if the specific heat of the soft drink is 4350 J/kg °C. 1.6. An engine operating in a cycle absorbs 5000 cal of the heat from a heat source and performs 2000 cal of work. Calculate: (a) The amount of heat discarded in this cycle (b) The efficiency of the engine

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Question 5 Not complete Marked out of 2 A system undergoes a cycle consisting of four processes. In the first it receives 10 kW of heat and it does 4 kW of work in the second process. If the system rejects 5 kW of heat in the third process then the work done in the fourth process is given by which of the following? Select one: О а. 1 kw O b. 6 kW О с. 9 kw O d. 15 kw O e. 5 kw Check

Please answer it in 1hr. Second Law of Thermodynamics Please show soln. step by step

1:50 & If a load of 460N was lifted by an effort of 144 N. Then the effort resulted in a 60 m movement. The load moved the distance of 19 m. A.) Calculate the efficiency of the system. B.) Draw a labeled diagram and explain what going on.

Question #3: Given: A 100 Kg roller coaster car has an initial velocity of 5m/s. It starts from a height H1=50m. H2 H1=50m a) Find the H2 for the following three cases: case 1) velocity of the roller coaster car is 0 m/s case 2) velocity of the roller coaster car is 2.5 m/s case 3) velocity of the roller coaster car is 5 m/s b) plot velocity of the roller coaster car (0, 2.5 and 5) versus H2 from parts ab and c H2 [m] Velocity [m/s]

A heat pump with the COP of 3.8 supplies heat at the rate of 289 kJ/min. If a bar heater was used and the electricity cost R2.50 per kWh peak and 200 cents off-peak , how much would be saved using the heat pump for 7 days if the off-peak hours are from 22:00 hr to 6:00 hr for every day of the week.  Provide the answers to 2 decimal places and insert the unit in Rands after the answer

Part a) Determine the power in hp delivered by the motor when the elevator is moving down at a constant speed of 1 ft/s.  Part b)  Determine the power in hp delivered by the motor when the elevator has an upward velocity of 1 ft/s and a deceleration of 0.18 ft/s2.

An electric hot water heater consumes 3.1 kilowatts of electricity and converts it to heat. How long will it take the water heater to heat a 67 gallon tank of water from 10 degrees Celsius to 50 degrees Celsius? (1 kilogram of water is 0.37 gallons, 1 Calorie = 4200 J).  It may be helpful to refer back to the weekly handout for guidance on this problem. Your final answer should be in minutes (rounded to the nearest 10 minutes).

Q1. The following data is obtained during geothermal drilling operation. Rock density = 1550 kg/m ³, heat capacity of the rock = 0.00163 J/kg K, temperature difference = 80 K. How much will be the thermal heat content of the rock at the geothermal site? Discuss about geothermal gradients their importance in energy exploration. Do you think utilization of geothermal energy worldwide is increasing yearly? Justify your answer. Do you think the geothermal energy available in this site can be used for a metal melting industry?

Question 24 A windmill operating at 50% efficiency sweeps out a disc with a 11 m radius. Calculate the ideal power produced when the wind speed is 13 m/s. Assume the air density is 1.2 kg/m². Give your answer in Watts to the nearest whole number.

8:  The kinetic energy E of a body is proportional to its weight W and the square of its velocity v.  A 10 lb body moving at 6 ft/sec has an 8 ft – lb of kinetic energy.  How much is the kinetic energy of a 2 ton ( 4,000 lb ) truck speeding at 45 kph ( 66 ft/sec )?. Select one: a. 268,400 ft – lb b. 325,500 ft – lb c. 387,200 ft – lb      d.  258,900 ft - lb

27.) A 13-V storage battery delivers current at the rate of 50 A. In a 27-min period, the heat lost from the battery is 92.74 kJ. What is the change in internal energy in kJ of the battery for the discharging period?

A.) A power plant is said to have a plant use factor of 48.5% and a plant capacity factor of 42.4%. How many hours did it operate during the whole year?  B.)A central station has annual factors as follows; Load Factor 58.5%; Plant Capacity factor 40.9%; Plant Use Factor 45.2%. The reserve carried over and above the peak load is 8900kW. Find annual energy production in kW-hr

20 Ib 02) Given the figure attached, Determine the following: 200 kg D • 1) What is magnitude of Rand Cr in pt D? 20 AN pr (Unit must be in N and kN-m) • 2) What is the magnitude of R and Cr in pt B? 2FT 200 kg (Unit must be in N and kN-m) • 3) Unit Vector of R in the system. • 4) Direct Cosines of Cr in pt D.

Solve question 2 based on the answer of question 1.  You have a natural gas furnace in your home that used 78,500 cubic feet of natural gas for heating last winter. Your neighbor has a furnace that burns heating oil and used 516 gallons of heating oil last winter. You can convert the natural gas and heating oil consumption data into Btu to determine which home used more energy for heating. Natural gas BTU:  1,028 Btu per cubic foot Oil BTU: 138,590 Btu per gallon   Natural Gas BTU= 80,698,000  Oil BTU                = 71,512,440    The home that used a natural gas furnace used more energy for heating. 2.- You need a new furnace for your home, and you are comparing systems that use natural gas and heating oil. One factor to consider is the cost of the fuel. You can compare the price of the fuels on an equal basis by dividing the price per unit of the fuels by the Btu content per unit of the fuels to get a price per million Btu. Assume Natural gas price = $10.50 per thousand cubic…