# Power - math problems

Power is the amount of work done (energy supplied) per unit time. In physics, power is the amount of energy transferred or converted per unit time. In the SI units, the unit of power is the watt, equal to one joule per second. Other units are, for example, 1 hp (one horsepower; 1 hp = 735.5 W) and then derived units such as kW - kilowatt.#### Number of problems found: 264

- Gain

Find the gain whenever the output power is 21x the input power. - Decibel

A circuit has an input power of 58 mW. Its output power is 6 mW. What is the loss in decibels? - 3 phase load

Two wattmeters are connected to measuring power in a 3 phase balanced load. Determine the total power and power factor if the two wattmeters read 1000 watts each (1) both positive and (2) second reading is negative - Simplest form

Find the simplest form of the following expression: 3 to the 2nd power - 1/4 to the 2nd power - Orlík hydroelectric plant

The Orlík hydroelectric power plant, built in 1954-1961, consists of four Kaplan turbines. For each of them, the water with a flow rate of Q = 150 m^{3}/s is supplied with a flow rate of h = 70.5 m at full power. a) What is the total installed power of the p - One third power

Which equation justifies why ten to the one-third power equals the cube root of ten? - Power

Number ?. Find the value of x. - Bulbs

In the box are 6 bulbs with power 75 W, 14 bulbs with power 40 W and 15 with 60 W. Calculate probability that a randomly selected bulb is: - Motor physics

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

What is the power output of kettle 2 kW with efficiency 90%? - Power line pole

From point A, the power line pole is seen at an angle of 18 degrees. From point B to which we get when going from point A 30m away from the column at an angle of 10 degrees. Find the height of the power pole. - Powers 3

2 to the power of n divided by 4 to the power of -3 equal 4. What is the vaule of n? - Pump

What power has a pump output to move 4853 hl of water to a height of 31 m for 8 hours? - Unknown number 7

Calculate unknown number whose 12th power when divided by the 9th power get a number 27 times greater than the unknown number. Determine the unknown number. - Electric work

Calculate the work done by the electric forces passing the current of 0.2 A through the bulb in 10 minutes if the bulb is connected to a 230 V power supply. - Density 2

What is the density of a piece of driftwood that has the mass of 25 grams and a volume is 30 cm to the 3rd power. And how do I figure it out? - Motorcycle engine

The motorcycle engine has a constant power of 1.2 kW for 0.5 hours. How much work does the engine do? Express work in kWh and Ws units. - Granddaughter

In 2014, the sum of the ages of Meghan's aunt, her daughter and her granddaughter was equal to 100 years. In what year was the granddaughter born, if we know that the age of each can be expressed as the power of two? - Derivative problem

The sum of two numbers is 12. Find these numbers if: a) The sum of their third powers is minimal. b) The product of one with the cube of the other is maximal. c) Both are positive and the product of one with the other power of the other is maximal.

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