P110/120: Energy/Energy & Technology Fall 2015
Homework 02
1 What is the potential energy of the water in a lake of surface area 10 square kilometers, with an average depth of 15 m, and elevation above the electrical generator of 200 m? (Note that you can ignore 15 m depth of the water compared to the 200 m elevation, i.e., use the total mass of the lake at an elevation of 200 m. Also, a cubic meter, i.e., 1 m3, has a mass of 1000 kg. The wonders of the metric system!
PEG = weight x height= mgh g=9.8m/s2 m= 10km2 x 1000m x 1000m = 107m2 107m2 x 15= 1.5 x 1.8m3 = 1.5 x 1011kg
E= 1.5 x 1011kg (9.8m/s)2 (200m)= 1kg/s2 = 1 Joule
2. The per capita rural consumption of household energy in some Bangladesh villages is 7 x 109 J/year.
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A household furnace has an output of 100,000 Btu/hr. What size electrical heating unit (in kW) would be needed to replace this?
1Btu= 0.002928104kW (conversion table online)
100,000 Btu(0.0002928104kW)= ~29.281kW
4. An engine performs 5000 Joules of work in 20 seconds. What is its power output in kilowatts and in
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The lights in our Swain West 007 lecture room were accidentally left on overnight (5:00 p.m. to 8:00 a.m., i.e., 15 hours). If electricity costs \$0.10/kWh, how much does this oversight cost if the energy consumption of the lights is 2200 W? kWh= 2200W/1000= 2.2kWh 2.2kWh x 15 hr = 33 kWh cost= 33 kWh x 0.10kWh = $3.30
6. A small stream flowing at a rate of 8 liters per second has a vertical drop of 1.5 m. What is the maximum power that you can obtain from this stream? (1 liter of water has a mass of 1 kg).
1L water= 1kg water, so mass= 8kg h=1.5m P=E/t E=mgh
E= 8 (9.8m/s2) (1.5)= 107.6 J Watt= 1Joule/Sec
P=107.6 J/1s= 107.6 W
7. If a 60-kg sprinter running at 10 m/s could convert all of her kinetic energy into upward motion, how high could she jump?
KE= 1/2mv2 =mgh g=9.8m/s2 h=v2/2g = 102 (2 x 9.8) = 5.1m
8. If a coal-burning electrical generating plant burns 2 tons of coal to generate 6000 kWh of electricity, calculate the efficiency of the plant as the ratio of electricity output to fuel energy input (refer to Table 3.4).
1 ton coal= 25 x106Btu 1kWh= 3413
The audience for writing project one: summary and response will be my classmates and my instructor, Avon Waters. I am writing this for English 111 – an online Ivy Tech college course. This is the first writing project of four for semester one. The assignment is to select a core reading resource from the group listed and perform a summary and response style paper, using proper APA formatting and introducing the concept of a situation analysis. The core reading piece I have selected is one that personally interested me, as it deals heavily with history and facts versus opinions and controversy. This will be in APA format, as with every other paper written in this course. My goal with this paper is to offer additional insight into the piece I
from the work surface, if any. Our results are set out below. Time (mins) : 0 - Height from bench (cm) -.. Temperature reached (d. c.). Water Volume (cm cubed).
From working out how much fuel has been used I can work out how much
In this inquiry the relationship between force and mass was studied. This inquiry presents a question: when mass is increased is the force required to move it at a constant velocity increased, and how large will the increase be? It is obvious that more massive objects takes more force to move but the increase will be either linear or exponential. To hypothesize this point drawing from empirical data is necessary. When pulling an object on the ground it is discovered that to drag a four-kilogram object is not four times harder than dragging a two-kilogram object. I hypothesize that increasing the mass will increase the force needed to move the mass at a constant rate, these increases will have a liner relationship.
The Darby Company is re-evaluating its current production and distribution system in order to determine whether it is cost-effective or if a different approach should be considered. The company produces meters that measure the consumption of electrical power. Currently, they produce these meters are two locations – El Paso, Texas and San Bernardino, California. The San Bernardino plant is newer, and therefore the technology is more effective, meaning that their cost per unit is $10.00, while the El Paso plant produces at $10.50. However, the El Paso plant has a higher capacity at 30,000 to San Bernardino’s 20,000. Once manufactured, the meters are sent to one of three distribution centers – Ft. Worth, Texas, Santa Fe, New Mexico and Las Vegas. Due to the proximity of El Paso to Ft. Worth, they are only plant to ship to Ft. Worth. The costs associated with each shipment are described in detail in Appendix 2.2A. From these distribution centers, meters are shipped to one of nine customer zones. The Ft. Worth center services Dallas, San Antonio, Wichita and Kansas City, the Santa Fe center services Denver, Salt Lake City, and Phoenix, and the Las Vegas center ships to Los Angeles and San Diego.
+ 10(926) 17102 + 21148 = - 4046 joules Pentan-1-ol + Oxygen Carbon dioxide + Water 2 C 5 H 11 OH + 15 O 2 10 CO 2 + 12 H 2 O 2(6747) + 15(496) + 10(1486) + 12(926).
This is a picture of a hydroelectric dam in Russia that hada 6G-watt power generation loss. This led to 75 deaths due to turbine failure.9
Based on my collected data, the energy consumption for my refrigerator alone is approximately 38% of the average energy consumption per day. (The energy consumption of the refrigerator is the highest).
F = ma : where F is force; m is the mass of the body; and a is the acceleration due to that particular force
The first type of renewable energy is hydroelectric energy or well known as hydropower. In greek word, hydro means water and thus hydroelectric energy refers to electricity generated using flowing water at high velocity. Lutgens and Tarbuck (1992, p. 163) stated that “running water is of great importance to people as we depend upon rivers for energy, travel and irrigation”. Continuous availability of water in universe made water to be the main source of hydroelectric energy. Water has been widely utilized by mankind since the beginning of civilization and wate...
Based on Laurel Nesbit, a program assistant in the Office of Sustainability here at UF, our campus manages to utilize 470,000 Megawatts of energy annually. This figure is generated from all the energy-consuming gadgets that operate on our campus on a daily bases. These gadgets include computers that are left turned on over the night even they are not in use, copiers, and the fume hoods in our laboratories. Admittedly, the success and the health of wellbeing of the students is contingent upon some of these equipment. For instance, the laboratories need the fume hoods in order to keep the experimenters safe. Instead of casting these necessities away, we can develop alternatives which will be capable of generating energy in order to compensate for the electricity that we endlessly
Hydropower, the use of water to power machinery or produce electricity, provides the most renewable energy in the United States, and uses alternating current in most modern plants ("Hydropower…”). Hydropower relies on the water cycle and is a clean fuel source; it doesn’t pollute the environment like plants that burn fossil fuels. It is by far the most efficient way to generate electricity, being half the cost of using nuclear power, two-fifths the cost of using fossil fuels, and a quarter the cost of using natural gas ("Wind and Water…”). Also, hydropower is not subject to market fluctuations of embargos, and the average lifespan of a facility is 100 years. Hydropower also has many non-energy benefits such as water supply, flood control, navigation, irrigation, and recreation. However, it does face many environmental challenges such as impacts to aquatic habitats, aesthetic alterations of landscapes, changes to water quality, and interruptions of marine life ("Hydropower…”).
Household energy conservation is a very practical and realistic approach to conserving energy within our society. US households consume a tremendous amount of natural gas as well as electric energy. It has been calculated that the amount of energy consumed within the US increased exponentially from about 1850 to 1975. If energy continued to increase at this rate, we would be experiencing severe energy shortages in our current society. Luckily, steps towards conservation, including various energy regulations, have curbed that growth somewhat, brining the predicted 160 Qbtu/yr for the year 2000 down to around 93.8 Qbtu/yr by the year 1996. However, household energy usage is still a major issue as households consume about 38% of the total consumed energy and contribute greatly to natural gas consumption and issues such as global warming. Therefore, it is important that people understand how we use energy in the household and what steps can be taken to conserve that energy.
Hydroelectric Power Plant is when electricity is generated when water in an uphill reservoir flows downhill. The gravitational potential energy of the water changes to kinetic energy of the flowing water which drives the turbines to generate electricity. The efficiency is more than 90%. The environmental impact is Floods large area and affects the ecology of the area, May cause drought downstream if not managed properly, does not cause ai...
The energy that is produced by hydropower, is used by the mankind to do work or to