# efficiency

1,029 results

**Physics**

A typical photo-voltaic cell delivers 4.2×10^−3W of electric energy when illuminated with 0.15W of light energy. What is the efficiency of the cell?

**Physics**

A pulley system lifts a 500-lb block 1.0 foot with an effort of only 50 lb. If the 50 lb moves 30 feet, calculate the efficiency of the pulley system.

**Physics**

A mechanical device requires 420 J of work to do 230 J of work in lifting a crate. What is the efficiency of the device? I keep getting 0.5% am I right?

**Science-y Math-y Stuff**

A machine with 80% efficiency does 4,000 J of work. Using the machine how much work did you do? NEED HELP! PLZ REPLY SOON

**Physics**

A hydraulic hoist has a ram of 30 cm diameter and a plunger of 1 cm diameter. If 70 N effort is applied to the plunger and the efficiency is 80%, find the maximum load it can raise.

**cars/fuel efficiency (chem)**

2.Which car would you recommend for a person who travels only 5 miles to work each day? How would I figure this out? Like... something about highway mileage?

**physics**

A heat engine has a hot reservoir of 680°C and a cold reservoir of 220°C. What is the efficiency of the engine?

**Physics**

A heat engine has a hot reservoir of 680°C and a cold reservoir of 220°C. What is the efficiency of the engine?

**physics**

A heat engine has a hot reservoir of 680°C and a cold reservoir of 220°C. What is the efficiency of the engine?

**physics**

what is efficiency of carnot engine between the temperature of 100 degree centigrade and 60 degree centigrade

**Physics**

In a simple machine, the energy input is 120j. If the efficiency of the machine is 80%. Calculate the energy output

**English**

Please check if my memo is correct MEMORANDUM To: Managers of Semper Absum Insurance From: Walter smith Date: October 29, 2008 Re: Increase Employees work efficiency Effective from one week from today, all employees must have their one-hour lunchtime away from their desks. ...

**economic**

Do a google search on the concept of a “flat tax.” Explain how this tax scheme works and does it meet the criteria of tax efficiency and tax fairness/equity?

**physics**

An engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating cycle. What is the efficiency of the engine?

**Information Technology**

explain how facebook has used two (2) design elements to enhance its appearance and Justify your response in terms of either efficiency (cost, time or effort) or effectiveness (quality of output, accuracy, presentation and comprehensiveness).

**ACCOUNTING**

Padding a budget __________________________________. (Points : 1) A is a smart use of company funds by a manager B does little to advance organizational efficiency C may induce wasteful spending D is impacted by more than one of the solutions listed here ANSWER B

**ECONOMICS**

For the following questions, you are provided with two statements. Choose the two economic goals THAT ARE MOST IN CONFLICT when considering the difference between the two statements. 1) In a market system, a person is entitled to earn as high an income as possible with no ...

**managerial accounting**

Tusk pty ltd uses standard costs system for its single product in which variable manufacturing overheads is applied on the basis of direct labour hours. The following information is given: Standard costs: Raw material[R16per kg] Per unit R 24.00 Direct labour[0.75hour] p er ...

**chemistry**

In Europe, gasoline efficiency is measured in . If your car's gas mileage is 20.0 km/l, how many liters of gasoline would you need to buy to complete a 142km trip in Europe?

**PHYSICS**

A person with skin area 2 m2 and 0.97 radiation efficiency is at rest and has a skin temperature of 28 C in an environment with a uniform temperature of 22 C .Calculate the heat loss rate in watts

**PHYSICS**

A person with skin area 2 m2 and 0.97 radiation efficiency is at rest and has a skin temperature of 28 C in an environment with a uniform temperature of 22 C .Calculate the heat loss rate in watts

**physics**

a. A person with skin area 2 m2 and 0.97 radiation efficiency is at rest and has a skin temperature of 28 C in an environment with a uniform temperature of 22 C Calculate the heat loss rate in watts

**physics**

a. A person with skin area 2 m2 and 0.97 radiation efficiency is at rest and has a skin temperature of 28 C in an environment with a uniform temperature of 22 C Calculate the heat loss rate in watts

**marketing**

Delivering the value proposition is also known as: A. endless chain marketing. B. situational distribution efficiency. C. wholesaling. D. supply chain management. My answer is D, is that correct?

**physics**

A certain power plant puts out 520MW of electric power.Estimate the heat discharged per second, assuming that the plant has an efficiency of 34%

**college**

Explain why, in terms of job performance and efficiency, knowing medical billing terms is critical for working in the health care field. Respond in at least 150 words and provide specific examples.

**Principles of finace**

How do you find use the annual net profit with the payables and inventory costs to determine the total annual cost a firm would need to achieve the industry level of operational efficiency?

**Science**

Ecology, Plants(Producers)? I was wondering if plants or producers vary a little or a lot in their efficiency at producing joules for human consumption? And could you suggest reasons for this variation?

**Science**

Ecology, Plants(Producers)? I was wondering if plants or producers vary a little or a lot in their efficiency at producing joules for human consumption? And could you suggest reasons for this variation?

**physics**

A box weighing 100 newtons is pushed up an inclined plane that is 5 meters long. It takes a force of 75 newtons to push it to the top,which has a height of 3 meters. What is the efficiency?

**physics**

You exert a force of 455N in pulling 15.0m of rope using a pulley system to lift a 935N object 5.0m. What is the efficiency of the pulley system? Please help, I appreciate it a lot.

**Physics**

A reversible engine converts 1/6 of the heat input into work. When the temperature of the sink is reduced by 62C, the efficiency of the engine is doubled.What are the temperarure of the source and sink?

**physics**

Due to a tune-up, the efficiency of an automobile engine increases by 4.00%. For an input heat of 1530 J, how much more work does the engine produce after the tune-up than before?

**History**

Efficiency was a central theme of the reform movement. Who of the following was not an example of someone striving to examine every aspect of life itself and determine, often through new scientific principles, how to do more work with less energy?

**physics**

A student pulls a (34) kg box a distance of (13.50) m up a ramp set at 25.8o using a force of (181) N applied parallel to the ramp. Find the efficiency of the ramp. Give your answer in percent (%) and with 3 significant figures.

**The defects of ball mill**

The Ball Mill faults: (1) work efficiency is low, the power consumption unit. (2) the ball mill barrel rotational speed is low (about 15 ~ 27 r/min), if you use ordinary motor that. The average all need equipped with expensive reducer. (3) grinding medium in the impact and ...

**computer**

2. _____is applications software designed to help users be more efficient. (Points: 5) a.Assistance software b.Efficiency software c.Productivity software d.Software suites is it D

**physics**

A satellite circling the earth has an average power consumption of 370.0 W. Assuming 5.4% efficiency for conversion of solar energy to electrical energy, what area is required for the solar panels?

**The defects of ball mill**

The Ball Mill faults: (1) work efficiency is low, the power consumption unit. (2) the ball mill barrel rotational speed is low (about 15 ~ 27 r/min), if you use ordinary motor that. The average all need equipped with expensive reducer. (3) grinding medium in the impact and ...

**Physics**

a person's metabolic processes can usually operate at a power of 6 W/kg of body mass for several hours at a time. If a 60 kg woman carrying a 12 kg pack is walking uphill with an energy-conversion efficiency of 20 percent, at what rate, in meters/hour, does her altitude increase?

**Physics**

An engine has a hot reservoir of 520K and a low temperature reservoir of 330K. What is the theoretical efficiency of this engine? Answer in units of % I got 36.5% but the teacher is saying that's wrong!! Please help with calculation.

**Physics - heat**

A .6 gm peanut is burned beneath 50g of water, which increases the temperature from 22 degrees to 50 degrees centigrade. Assuming 40% efficiency, show that the peanut's food value is 3500 calories.

**physics**

A car engine has 90 kW and an efficiency of 12 percent. Let's assume a simple model of air friction, Fair=Kv2 , with K=027kgm for this car. If there is no other friction, and no winds, what is the maximum speed it can reach?

**Physics**

An electrical generating plant operates at a boiler temperature of 220 deg C and exhausts the unused heat into a nearby river at 18 deg C. what is the maximum theoretical efficiency of the plant?

**Physics**

The system has two wheels and requires an effort of 12N to lift a load of 4kg at constant speed. Find M.A nd V.R.. Calculate work done by effort to raise load of 2m and efficiency of this machine.

**Physics**

An ideal gas heat engine operates in a Carnot Cycle between temperatures of 266 and 115°C. It absorbs 4250 cal per cycle at 266°C. What is its efficiency as a percentage

**Physics**

An ideal gas heat engine operates in a Carnot Cycle between temperatures of 266 and 115°C. It absorbs 4250 cal per cycle at 266°C. What is its efficiency as a percentage?

**Physics**

A 100 hp motor raises a 200lb elevator 200 ft in 10 sec. The efficiency for the elevator system is 72.7% or 73%. How much energy is lost in 10 sec? Answer: 193 Btu Show work

**Business**

TCO 1) Employers provide tools and technology for their employees in order to: a. increase the cost of production and profitability. b. improve their efficiency and productivity. c. to reduce corruption in business and eliminate scandals. d. encourage the private ownership of ...

**engineering**

A cast-iron saucepan of mass 1.4kg is filled with 5L of water at 15°C, placed on an electric hotplate, and bought up to boiling point. What is the cost of the energy used if the electricity costs 10 cents per kWh and the hotplate has an efficiency of 70%.

**Direct way to improve yield of ball mill**

The Ball Mill as a general grinding equipment, is widely used in dressing, building materials and chemical industry, ball mill can be divided into dry and wet type two kinds of grinding way. According to the row of ore in different ways, and can be divided Grate Ball Mill and ...

**Economics**

Suppose two passengers end up with a reservation to Los Angeles. Two alternatives are proposed: a. Toss a coin b. Sell the ticket to the highest bidder Compare the two options from the standpoint of efficiency and equity.

**physics**

The engine of a large ship does 2.05 multiplied by 108 J of work with an efficiency of 4.00%. (a) How much waste heat (J) is produced? (b) How many barrels of fuel are consumed, if each barrel produces 6.00 multiplied by 109 J of heat when burned?

**physics**

a 65 kg bag is dragged along a 12m ramp in order to get from the ground to the floor of the loading dock 2m above the ground. determine the efficiency of of the ramp. I don't understand how to the find the energy output and input.

**Physical Science**

When you do 100 J of work on the handle of a bicycle pump, the pump does 40 J of work pushing the air into the tire. What is the efficiency of the pump?

**physics**

an engine pumps of 100 kg of water through a height of 10m in 5 second. Given that the efficiency of engine is 60%. If g=10m/s^2 the power of engine is

**math**

The efficiency e of a gasoline engine as a function of its compression ratio r is given by e =1− r1−γ , where γ is a constant. Find γ for e = 0.55 and r = 7.5.

**physics**

a pump fills a tank of capacity 300 m^3 in 5 hours.the tank is situated at a height of 20 m.if the efficiency of the tank is 65%. then calculate the power of the engine which has driven the pump.

**Math natural logarithms**

The efficiency e of a gasoline engine as a function of its compression ratio r is given by e =1− r^(1−γ) , where γ is a constant. Find γ for e = 0.55 and r = 7.5

**physics**

A typical photovoltaic cell delivers 3.8×10−3 {\rm W} of electric energy when illuminated with 0.14 {\rm W} of light energy. what is the energy efficiency of the cell?

**physics**

A certain heat engine does 8.0 kJ of work and dissipates 8.00 kJ of waste heat in a cyclical process. (a) What was the heat input to this engine? (b) What was its efficiency?

**physics**

A certain heat engine does 8.0 kJ of work and dissipates 8.00 kJ of waste heat in a cyclical process. (a) What was the heat input to this engine? (b) What was its efficiency?

**Physics**

A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)

**Physics**

A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)

**Physics**

A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)

**physics**

Ayesha exerts a force of 186 N on a lever to raise a 2.70 × 103-N object to a height of 29.0 cm. If the efficiency of the lever is 83.3 percent, how far does Ayesha move her end of the lever?

**Physics**

A body of mass 7.5kg is to be pulled up along a plane which is inclined at 30degree to the horizontal. If the efficiency of the plane is 75%,what is the minimum force required to pull the body up the plane?

**social studies**

-Lyndon B. Johnson Former President Lyndon felt that the most important first step in the war against poverty is? A) full employment B) efficiency in government C) our natural defense D) private and public economics

**health**

Explain why, in terms of job performance and efficiency, knowing medical billing terms is critical for working in the health care field. Respond in at least 150 words and provide specific examples.

**Physics**

A nuclear power plant has an electrical power output of 1200 MW and operates with an efficiency of 31%. If excess energy is carried away from the plant by a river with a flow rate of 1.0 x 10^6 kg/s, what is the rise in temperature of the flowing water?

**Physics**

Calculate the electric power produced by a wind mill, when the wind speed is 10 m/s and the radius of the rotor circle (wing length) is 15 m. The density of air is 1.25 kg/m3. The eefficiency of the wind mill is 45%.

**physics**

A boy exerts a force of 210 N on a lever to raise a 1.25 103 N rock a distance of 12 cm. If the efficiency of the lever is 88.7%, how far did the boy move his end of the lever? Thanks for all your help :) <3, PhysicsCrazy<3

**Chemistry**

If we have solution of 4g CH3COONa and 4g NaOH obtained NaCl with efficiency 90% we have to calculate pH oh Nacl and we know that Ka= 1.8x10ˆ-5. Pleas help me i have exam tnext weak Im strudent but I don't undestant this???

**Physics...please help me out..**

A body of mass 7.5kg is to be pulled up along a plane which is inclined at 30degree to the horizontal. If the efficiency of the plane is 75 %, what is the minimum force required to pull the body up the plane?

**Science**

You do 100 J of work in pulling out a nail with a claw hammer. If the hammer does 70 J of work, what is the hammer's efficiency?

**biology**

If a particular experiment were known to have a transformation efficiency of 3 x 10^3 bacteria/µg of DNA, how many transformant colonies would be expected to grow on the LB/amp/ara plate? You can assume that the concentration of DNA and fraction of cells spread on the LB agar...

**maths help me**

an engine pumps water from a river 10m an below its own level and discharge it through a nozzle of diameter 10cm with a speed of 50m/ s.find the power required assuming a.no losses b.70% efficiency.water weighs 10^3kgm^-3 {g=10ms^-2} help me

**chemistry**

suppose a new car travels 70.0 miles on one gallon of gasoline with 40% efficient engine. how much fuel is wasted annually due to energy efficiency if in one yr, 478.26 gallons of fuel is burned?

**Physics**

A nuclear power plant has an electrical power output of 1200 MW and operates with an efficiency of 31%. If excess energy is carried away from the plant by a river with a flow rate of 1.0 multiplied by 10^6 kg/s, what is the rise in temperature of the flowing water?

**Physics**

A nuclear power plant has an electrical power output of 1200 MW and operates with an efficiency of 31%. If excess energy is carried away from the plant by a river with a flow rate of 1.0 multiplied by 10^6 kg/s, what is the rise in temperature of the flowing water?

**physics**

a 70-kg man climbs a mountain 1200 m high (measured from the base) in 4 h and uses 9.8 kcal/min. calculate his power consumption in watts. what is his power output in useful work? what was the efficiency of this man during the climb?

**physics**

A nuclear power plant has an electrical power output of 1900 MW and operates with an efficiency of 32%. If excess energy is carried away from the plant by a river with a flow rate of 1.0 106 kg/s, what is the rise in temperature of the flowing water? °C

**us history**

Which of these was a consequence of a growing textile industry in the United States? Decreased need for unskilled workers Decreased number of inventions Increased cost and reduced efficiency Increased demand for slave labor is it d pls help me

**physics**

A 3000-kg truck needs a propeling steady force of 1400 N to travel at a speed of 40 mpg. What is the MPG for the truck if its engine efficiency is 27%? Heat released from one gallon=136,500,000 J and 1 m= 1609 m.

**Physics**

A block and tacle of 6 pulley is used to raise a load of 300n steadily through a height of 30m if the workdone against friction is 2000j. calculate the workdone by the effort,the applied effort,the efficiency of the system

**Chemistry**

Rank the crystal lattice structures in order of decreasing efficiency of space in the structure? Face centered cubic, body centered cubic, simple cubic, hexagonal close packing.

**simple machines**

A box with a force of 100N is pushed up an inclined plane. It takes a force os 75N to push it to the top. What is the efficiency of the inclined plane?

**economics**

Discuss the effects on efficient behavior of different liability rules, including comparative negligence. Include in your discussion an analysis of the efficiency of the various rules and discuss the differing costs of administering the rules.

**Math**

A river does 6,500 J of work on a water wheel every second. The wheel's efficiency is 12%. a. How much work in joules can the axle of the wheel do? b. What is the power output of the wheel in 1 s?

**physics**

You use an inclined plane to move furniture into a truck. You perform 224 kJ of work, but only do 91 kJ of useful work. What is the efficiency of the inclined plane?

**economics**

When policymakers set prices by legal decree, they a. improve the organization of economic activity. b. obscure the signals that normally guide the allocation of society’s resources. c. are usually following the advice of mainstream economists. d. are demonstrating a ...

**Economics**

When policymakers set prices by legal decree, they...? a. obscure the signals that normally guide the allocation of society’s resources. b. are usually following the advice of mainstream economists. c. improve the organization of economic activity. d. are demonstrating a ...

**Physics**

The oven draws 1100W of power, and you have determined that it heats with an efficiency of 51%. Using this information, determine the time t it would take to bring 240mL of water from 25C to 100C . Note that 4.2 J of energy is required to raise the temperature of 1.0mL of ...

**bio**

Determine the number of colonies counted on the LB plate in the following transformation experiment. The amount of plasmid on the plate being counted was 0.04 micrograms. The transformation efficiency was calculated to be 4 x 10^3.

**physical science**

A river does 6,500 j of work on a water wheel every second. The wheel efficiency is 12%. A. How much work in joules can the axle of the wheel do? B. What is the power output of the wheel in 1 s?

**Chemistry**

If 682000 kJ could be transferred with 100% efficiency to water, what volume of water, in liters, could be heated from 8.6 degrees Celsius to 60.0 degrees Celsius as a result?

**science**

1.) what energy transformation are taking place when a ball is dropped from 1.0 m, bounces and tries to 0.80 m, bounces again and rises to 0.64m? What is the efficiency of the energy transformations of ball during a bounce?

**Physics**

a 75 w compact fluorescent bulb operating at 30% efficiency. Calculate the amount of energy lost to heat and the amount of energy converted into light after the bulb has been on for 2.0h.

**physics**

The useful energy output of an engine is 1.50 × 103 kJ and the total mechanical energy input is 4.32 x 103 kJ . The efficiency of the engine is __________%

**Algebra 2**

A cars fuel efficiency is 24 miles per gallon and can be driven 324 miles with a full tank of gas. Write an expression for the amount of miles that be driven after X gallons have been used.