# Energy - problems

- Electric input power

Solve problems related to electric power: a) U = 120 V, I = 0.5 A, P =? b) P = 200 W, U = 230 V, I =? c) I = 5 A, P = 2200W, U =? - Excavation

Mr. Billy calculated that excavation for a water connection dig for 12 days. His friend would take 10 days. Billy worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met? - Engineer Kažimír

The difference between politicians-demagogues and reasonable person with at least primary education beautifully illustrated by the TV show example. "Engineer" Kažimír says that during their tenure there was a large decline in the price of natural gas, pri - Rates

When gas consumption, the consumer may choose one of two rates: rate A - which pays 0.4 € per 1 m^{3}of gas a flat monthly fee of 3.9 € (regardless of consumption) rate B - which pays 0.359 € per 1 m^{3}of gas a flat monthly fee of 12.5 € From what monthl - Pump

What power has a pump output to move 4853 hl of water to a height of 31 m for 8 hours? - Three drivers

Three driversdriving the same direction found that they have same amounth of gasoline. The first is enough to go 6 km, 4 km second and third 3km. Gasoline they divided so all three just drove to the nearest petrol station. How many km away was a petrol sta - Motor physics

Car traveling at 130 km/h on the highway. Pulling power of the motor is 8 kN. Determine engine power in kW. - Cubic

Convert 660 m^{3}of natural gas volume to energy units kWh. Combustion of 1 cubic meter of natural gas is released energy 10.55 kWh. - Bath

In the bath is 30 liters of hot water. Then added 36 liters of cold water at temperature of 19 °C decreased temperature of water to 41 °C. What was the initial temperature of the hot water? - Cows

20 cows has food for 60 days. We reduce the dose to two-thirds for 18 cows. How many days will be fed? - MPG

306 miles a week fills up twice a week. Each fill is 26 gallons. What is gas mileage of the car? - Decibel

A circuit has an input power of 50 mW. Its output power is 8 mW. What is the loss in decibels? - Elevator

In homes with more floor elevators are used. For passenger transport, the most commonly used traction elevator counterweight. The top of the shaft engine room with the engine. The car is suspended on a rope, which is guided up over two pulleys to the count - Car

At what horizontal distance reaches the car weight m = 1534 kg speed v = 85 km/h when the car engine develops a tensile force F = 1691 N. (Neglect resistance of the environment.) - Shot

Shot with a mass 43 g flying at 256 m/s penetrates into the wood to a depth 25 cm. What is the average force of resistance of wood? - Stand-by power

Determine the year-round consumption of appliances in stand-by mode. Stand-by mode is regime the unit continuously 24 hours consume a tiny amount of electricity. Typically are televisions, electric ovens, radios, computers, monitors, satellite receivers, w - Gasoline consumption Skoda MB

Consumption of cars for 100 km is 6.6 liters of gasoline 1 liter of gasoline costs € 1.274. How many euro grandfather spent when the car travelled 321 km. - Locomotive

Locomotive pulled a train permanent load of 200 kN horizontally along the track of 5km. What work it done? - Fuel mileage

You have 3/8 tank of fuel. Estimate fuel consumption @ 6mpg. Estimate speed @ 50mph. Your fuel tank holds 200 gals. Figure out fuel mileage. - Chocolate roll

The cube of 5 cm chocolate roll weighs 30 g. How many calories will contain the same chocolate roller of a prism shape with a length of 0.5 m whose cross section is an isosceles trapezoid with bases 25 and 13 cm and legs 10 cm. You know that 100 g of this.

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