Principles of Physics: A Calculus-Based Text
5th Edition
ISBN: 9781133104261
Author: Raymond A. Serway, John W. Jewett
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 7, Problem 35P
To determine
To determine: The total saving obtained by using one energy efficient bulb over its life time as opposed to using conventional bulbs.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
An elevator has an electrical power rating of 3.2 x 104 W. If the elevator takes 42 s to move up 3 floors (12 m total), what is its efficiency? Assume the mass of the elevator and its passengers is 1800 kg.
I have 72 lightbulbs in my house. 53 of these lightbulbs are 65 watt and the other 19 lightbulbs are 53 watt. I use the 65 watt lightbulbs an average of 10 hours a day and 53 watt an average of 12 hours a day. 1 kilowatt=1000 watts.
Estimate the energy used during 1 year by all the lightbulbs in my home?
An electric motor is rated at 10 horsepower (HP) and costs $800. Its full-load efficiency is specified to be 85%. A newly designed, high-efficiency motor of the same size has an efficiency of 90%, but costs $1,200. It is estimated that the motors will operate at a rated 10-HP output for 1,500 hours a year, and the cost of energy will be $0.07 per kilowatt-hour. Each motor is expected to have a 15-year life. At the end of 15 years, the first motor will have a salvage value of $50, and the second motor will have a salvage value of $100. Consider the MARR to be 8%. (Note: 1 HP= 0.7457kW.)(a) Determine which motor should be installed based on the PW criterion.(b) What if the motors operated 2,500 hours a year instead of 1,500 hours ayear? Would the motor selected in (a) still be the choice?
Chapter 7 Solutions
Principles of Physics: A Calculus-Based Text
Ch. 7.1 - By what transfer mechanisms does energy enter and...Ch. 7.1 - Consider a block sliding over a horizontal surface...Ch. 7.2 - Prob. 7.3QQCh. 7.2 - Prob. 7.4QQCh. 7.4 - Prob. 7.5QQCh. 7 - You hold a slingshot at arms length, pull the...Ch. 7 - An athlete jumping vertically on a trampoline...Ch. 7 - Prob. 3OQCh. 7 - Two children stand on a platform at the top of a...Ch. 7 - Answer yes or no to each of the following...
Ch. 7 - A ball of clay falls freely to the hard floor. It...Ch. 7 - What average power is generated by a 70.0-kg...Ch. 7 - In a laboratory model of cars skidding to a stop,...Ch. 7 - At the bottom of an air track tilted at angle , a...Ch. 7 - One person drops a ball from the top of a building...Ch. 7 - Prob. 2CQCh. 7 - Does everything have energy? Give the reasoning...Ch. 7 - Prob. 4CQCh. 7 - Prob. 5CQCh. 7 - Prob. 6CQCh. 7 - A block is connected to a spring that is suspended...Ch. 7 - Consider the energy transfers and transformations...Ch. 7 - Prob. 9CQCh. 7 - Prob. 10CQCh. 7 - Prob. 1PCh. 7 - Prob. 2PCh. 7 - Review. A bead slides without friction around a...Ch. 7 - At 11:00 a.m, on September 7, 2001, more than one...Ch. 7 - A block of mass 0.250 kg is placed on top of a...Ch. 7 - A block of mass m = 5.00 kg is released from point...Ch. 7 - Two objects are connected by a light string...Ch. 7 - Prob. 8PCh. 7 - Prob. 9PCh. 7 - Prob. 10PCh. 7 - Prob. 11PCh. 7 - A crate of mass 10.0 kg is pulled up a rough...Ch. 7 - Prob. 13PCh. 7 - Prob. 14PCh. 7 - A block of mass m = 2.00 kg is attached to a...Ch. 7 - Prob. 16PCh. 7 - A smooth circular hoop with a radius of 0.500 m is...Ch. 7 - Prob. 18PCh. 7 - Prob. 19PCh. 7 - As shown in Figure P7.20, a green bead of mass 25...Ch. 7 - A 5.00-kg block is set into motion up an inclined...Ch. 7 - The coefficient of friction between the block of...Ch. 7 - Prob. 23PCh. 7 - Prob. 24PCh. 7 - Prob. 25PCh. 7 - Prob. 26PCh. 7 - A child of mass m starts from rest and slides...Ch. 7 - The electric motor of a model train accelerates...Ch. 7 - Prob. 29PCh. 7 - Prob. 30PCh. 7 - Prob. 31PCh. 7 - Sewage at a certain pumping station is raised...Ch. 7 - Prob. 33PCh. 7 - Prob. 34PCh. 7 - Prob. 35PCh. 7 - Prob. 36PCh. 7 - Prob. 37PCh. 7 - Prob. 38PCh. 7 - Prob. 39PCh. 7 - Prob. 40PCh. 7 - A loaded ore car has a mass of 950 kg and rolls on...Ch. 7 - Prob. 42PCh. 7 - A certain automobile engine delivers 2.24 104 W...Ch. 7 - Prob. 44PCh. 7 - A small block of mass m = 200 g is released from...Ch. 7 - Prob. 46PCh. 7 - Prob. 47PCh. 7 - Prob. 48PCh. 7 - Prob. 49PCh. 7 - Prob. 50PCh. 7 - Prob. 51PCh. 7 - Prob. 52PCh. 7 - Jonathan is riding a bicycle and encounters a hill...Ch. 7 - Prob. 54PCh. 7 - A horizontal spring attached to a wall has a force...Ch. 7 - Prob. 56PCh. 7 - Prob. 57PCh. 7 - Prob. 58PCh. 7 - Prob. 59PCh. 7 - Prob. 60PCh. 7 - Prob. 61PCh. 7 - Prob. 62PCh. 7 - Make an order-of-magnitude estimate of your power...Ch. 7 - Prob. 64PCh. 7 - Prob. 65PCh. 7 - Review. As a prank, someone has balanced a pumpkin...Ch. 7 - Review. The mass of a car is 1 500 kg. The shape...Ch. 7 - A 1.00-kg object slides to the right on a surface...Ch. 7 - A childs pogo stick (Fig. P7.69) stores energy in...Ch. 7 - Prob. 70PCh. 7 - Prob. 71PCh. 7 - Prob. 72PCh. 7 - A block of mass m1 = 20.0 kg is connected to a...Ch. 7 - Prob. 74PCh. 7 - Prob. 75PCh. 7 - Prob. 76PCh. 7 - Prob. 77PCh. 7 - Prob. 78PCh. 7 - A block of mass 0.500 kg is pushed against a...Ch. 7 - A pendulum, comprising a light string of length L...Ch. 7 - Jane, whose mass is 50.0 kg, needs to swing across...Ch. 7 - A roller-coaster car shown in Figure P7.82 is...Ch. 7 - Prob. 83P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Sewage at a certain pumping station is raised vertically by 5.49 m at the rate of 1 890 000 liters each day. The sewage, of density 1 050 kg/m3, enters and leaves the pump at atmospheric pressure and through pipes of equal diameter. (a) Find the output mechanical power of the lift station. (b) Assume an electric motor continuously operating with average power 5.90 kW runs the pump. Find its efficiency.arrow_forwardThe total consumption of electrical energy in the United States is about 1.0 1019 joules per year. What is the average rate of electrical energy consumption in watts? If the population of the United States is 300 million, what is the average rate of electrical energy consumption per person? The sun transfers energy to the earth by radiation at a rate of approximately 1.0 kW per square meter of surface. If this energy could be collected and converted to electrical energy with 40 % efficiency, how great an area (in square kilometers) would be required to collect the electrical energy used by the United States?arrow_forwardA typical photovoltaic cell delivers 4.0 × 10-3 W of electric energy when illuminated with 1.2 × 10-1 W of light energy. What is the efficiency of the cell?arrow_forward
- An electric refrigerator rated 400 W operates 8 hour/day. What is the cost of the energy to operate it for 30 days at Rs 3.00 per kW h?arrow_forwardAccording to the World Energy Council, the average household in Mexico consumes about 1600 kWh of energy per year. In Monterrey, Nuevo León, Mexico, the GHI Solar Map suggests that the average annual solar energy potential is about 1800 kWh/m2 per year. If solar panels are available in sizes of 1 m × 1 m with an efficiency of 17%, how many panels will be needed to power a house in Monterrey for a year? Question 10 options: 6 7 2 1arrow_forwardI often make tea in my microwave oven. I know that it takes two minutes to bring the temperature of a cup of water from room temperature to just about boiling: ready for the teabag. I looked up the characteristics of a microwave oven. Typically their power rating is about 1000 W, but I know that this is the power consumed from the power company, not the power delivered to the water. I looked up the efficiency of microwave ovens, and found that it is about 64%, meaning that a typical oven delivers 640 W to the water. I also looked up the frequency of the microwaves that an oven uses, and found thatf= 2,450 MHz. (a) How much energy is delivered to the water in the making of a cup of tea? (b) What is the wavelength of the microwave? (c) What is the energy of one microwave photon? (d) How many microwave photons are absorbed by the water in making a cup of tea?arrow_forward
- The average electricity consumption of a house in Gainesville is known to be 1,036 kWh in a month (One month = 30 days). They would like to install solar panels of 30 % efficiency to generate this electricity. Given that the average solar power density in Gainesville is 5.47 kWh/m2/day, how much surface area must the panels occupy? Calculate the result in m² but do not write the unit. Round off you E swer to a whole number (zero decimal place.)arrow_forward(a) What is the average power consumption in watts of an appliance that uses 5.93 kW · h of energy per day? Answer: ___________ W (b) How many joules of energy does this appliance consume in a year? Answer: ___________ Jarrow_forwardYou use a quantity of fuel with a total energy content of 19.02 MJ to power an engine. If the average output of the engine over 2 hours was 2.12 kW, what is the efficiency of the engine?arrow_forward
- A typical desktop personal computer uses around 100 W of power when carrying out intensive processing, such as running a video game. If you play such a game for 90 minutes, how much energy (in joules) will it use?arrow_forwardMany decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation. If energy cost $1.00 per million joules and the insulation was $4.00 per square meter, then calculate the simple payback time. Take the average for the 120 day heating season to be 15.0C.arrow_forwardThe metabolic power for walking is 316 W for Lili. For how long would Lili have to walk to use all the energy available in a can of soda, which energy content is 628 kJ (150 food calorie), in minutes? Your answer needs to have 3 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Kinetic Energy and Potential Energy; Author: Professor Dave explains;https://www.youtube.com/watch?v=g7u6pIfUVy4;License: Standard YouTube License, CC-BY