Advice 1: How to find efficiency

Coefficient of useful action shows the ratio of the useful work that is performed by a mechanism or device to expended. Often spent work take the amount of energy that the device consumes in order to perform the work.
You will need
• - the car;
• thermometer;
• calculator.
Instruction
1
In order to calculate the coefficient of useful action (CPA) divide the useful work Up to the work expended AZ and multiply the result by 100% (efficiency=AP/AZ∙100%). Get the result in percent.
2
When calculating the efficiency of the heat engine, useful work, consider the mechanical work done by a mechanism. For the spent work take the amount of heat generated by the burned fuel which is a source of energy for the engine.
3
Example. The average tractive power of the engine of the vehicle is 882 N. At 100 km it consumes 7 kg of gasoline. Determine the efficiency of its engine. First, find a good job. She is the product of force F for a distance S traveled by a body under the influence of AP=F∙S. Determine the quantity of heat allocated at burning 7 kg of gasoline, it will be spent working AZ=Q=q∙m, where q – calorific value of fuel, for gasoline it is equal to 42∙10^6 j/kg and m is the mass of fuel. Engine efficiency is equal to efficiency=(F∙S)/(q∙m)∙100%= (882∙100000)/( 42∙10^6∙7)∙100%=30%.
4
In the General case, to find the efficiency of any heat engine (internal combustion engine, steam engine, turbine, etc.) where the work is done by the gas has a coefficient of useful action is equal to the difference of heat given to the heater, Q1 and Q2 received by the fridge, find the difference between the warmth of the heater and of the refrigerator, and divide by the warmth of the heater efficiency= (Q1-Q2)/Q1. Here efficiency is measured in units of decimal fraction from 0 to 1 to convert the result into a percentage, multiply it by 100.
5
To get the efficiency of an ideal heat engine (Carnot), find the ratio of the temperature difference of the heater T1 and cooler T2 temperature the heater efficiency=(T1-T2)/T1. This is the maximum possible efficiency for a particular type of heat engine with given temperatures of the heater and of the refrigerator.
6
To find the spent motor work as the product of the power at the time of its execution. For example, if the motor of the crane capacity of 3.2 kW lifts a load weighing 800 kg to a height of 3.6 m for 10 s, then its efficiency is equal to the ratio of useful work AP=m∙g∙h, where m is the load mass, g≈10 m/S2 the acceleration of gravity, h is the height to which lifted the load, and spent working AZ=R∙t, where P – motor power t – the time it works. Will receive the formula for definition of efficiency=AP/AZ∙100%=(m∙g∙h)/(R∙t) ∙100%=%=(800∙10∙3,6)/(3200∙10) ∙100%=90%.

Advice 2: How to calculate efficiency

Coefficient of performance (COP) is a measure of the effectiveness of any system, be it a car engine, car or other mechanism. It shows how efficiently the system uses the received energy. To calculate efficiency very easily.
Instruction
1
Most often efficiency is calculated from the ratio of the useful energy system to all total received energy in a certain period of time. It is worth noting that efficiency has no specific units of measurement. However, in the school curriculum this value is measured in percents. This ratio, based on the above data, calculated by the formula:
η = (A/Q)*100%, where η ("ETA") is the required efficiency, A useful operation of the system, Q is the total energy, A and Q are measured in Joules.
2
The above method of calculating efficiency is not the only one, as the useful work of the system (A) is calculated according to the formula:
A = Po-Pi where Po - power system energy from the outside, Pi - loss of energy in the system. Expanding the numerator of the above formula, it can be written in the following form:
η = ((Po-Pi)/Po)*100%.
3
To the calculation of the efficiency was more clear and evident, it is possible to consider the examples.
Example 1: Useful work equal to 75 j, the sum expended for its operation energy is 100 j, it is required to find the efficiency of the system. To resolve this problem, apply the first formula:
η = 75/100 = 0.75 or 75%
Answer: the efficiency of the proposed system is 75%.
4
Example 2: Input to operate the engine energy is 100 j, the energy loss during operation of this engine 25 j is necessary to calculate efficiency. For a solution use the second formula of calculating the required ratio:
η = (100-25)/100 = 0.75 or 75%.
The responses in both examples are the same, because in the second case was more parsed data to the numerator.
Note
Many types of modern engines (e.g., rocket engine or turbowebguy) have several stages of its work, and each stage has its own efficiency, which is measured in any of these formulas. But to find the common ratio, you will need to multiply all known efficiency at all stages of operation of this engine:
η = η1*η2*η3*...*η.
Efficiency cannot be more than one, because during the operation of any system inevitably loss of energy.

Associated transport is a kind of transportation, consisting forthe load the vehicle is carrying out a blank run. Situation when vehicles have to travel without cargo are fairly common, and, both before and after the scheduled transfer order. For the enterprise the opportunity to take additional load means, at least, reduction of financial losses.
Instruction
1
Rate the effectiveness of the use of associated transportation specifically for your company. An important point to understand is the fact that the passing load may be transported to a time when the empty transport were forced to move after the implementation of the primary Tr. If your business such situations occur regularly, feel free to choose such a way to optimize traffic.
2
Estimate what the associated cargo weight and size to transport your vehicle. Associated cargo can be economically beneficial even if a portion of your cargo space of your car will be unoccupied.
3
Consider some of the main points of the route you will be able to take a passing load. The preferred if the goods you can obtain at the end point of the planned route and take him to the place where is located your transport company. But this situation may not always meet. Therefore, we consider also the possibility of some deviation from the route, having considered, of course, the economic feasibility of such changes.
4
Find out whether the return transportation of goods to the enterprise in which you make scheduled transportation. In this case, it is much easier to agree on the price issue and ensure reliability for more mutually beneficial cooperation.
5
Find some specialized Internet portals, providing information services in the field of transportation. As a rule, the websites of such companies have relevant sections, allowing you to find a passing load on your way and make a request. In most cases doing so requires at least registering on the website. It would be ideal if the information resource has built-in tools for logistics analysis of counter-offers.
6
Don't neglect the national transport when in a selected direction to transport the transported goods of small size from different customers. The transport must make Shuttle routes in selected areas.
Note
To find a passing load - quite easy! The main aim of our service is to search various downloads, which users can not only =with maximum convenience for themselves, but also absolutely free. With the help of our system, which is based on the use of modern information technology, to find the cargo very easy.
Likely that You have decided to buy or rent a large truck, with which You intend to earn money through transportation of cargo in Russia, CIS and Europe. Still, would You hire a driver or are going to ride on it, You'll need customers, i.e. the cargo for transportation. Then You certainly will think or have thought, where and how to find loads for your truck?

Advice 4: How to find useful work

The word "work" means primarily an activity which gives a man a livelihood. In other words, for her, he gets material compensation. However, people are willing in their spare time, or free of charge or for a nominal fee to participate in socially useful work to help the needy, improvement of backyards and streets, landscaping, etc. the Number of such volunteers probably would be more, but they often don't know where you might need their services.
Instruction
1
One of the most popular types of socially useful work is charity. It includes assistance to the needy and socially unprotected groups of the population: the disabled, the elderly, the homeless. In short, all those who for some reason was in a difficult situation.
2
Volunteers wishing to take active part in such assistance should contact the nearest charitable organization or departments of social assistance. Can inquire in the nearest Church – the priest probably knows who of his congregation in particular need of support.
3
You can also take the initiative to literally live in an apartment building probably live lonely pensioners, disabled people or single mothers, who have every ruble counts. Provide them all possible assistance. It does not necessarily have to be monetary donation – you can, for example, from time to time to go to the grocery store or the pharmacy for drugs.
4
A lot of people wish to participate in the improvement of his native city. They should contact the relevant agencies of the local municipality, for example, those who are responsible for the cleaning of territories, landscaping. The work is certainly there. In addition, it is possible, for example, on its own initiative to break a flower bed under the Windows of the house, to plant flowers.
5
There are people who are very loving animals who want to help street dogs and cats. If you belong to this category, contact with local organizations of animal rights activists with the owners or animal shelters. Well, if you live in a large city where there is a zoo, check with the administration if assistants care for the animals. Typically, these offers of help are welcomed with gratitude.
6
We should not forget about the education of the younger generation. If the enthusiastic volunteer can, for example, to teach in any school clubs or the centre of culture and creativity, it will bring this great benefit. In short, socially useful work for the concerned people, there are many, for every taste and possibilities. It would wish.
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