# Unit conversion + third power - practice problems

#### Number of problems found: 36

- Power consumption

The price of electricity is ₱6.50 per kilowatt hour (kWh). If a television with 120 W power consumption ran from 7:30 AM to 12:30 PM, how much electricity was consumed? - What power

What power should the radiator have in a room 5x4 meters with a height of 3 meters? Hint: Calculate 35 watts per meter ^ 3 in case you need 22 degrees in the room but you need about 24 degrees in the bathroom. It's an old heating cheat, but it will defini - The output

The output voltage of the transformer is 880 V. The secondary coil has 1200 turns. Find the voltage to which the primary coil is connected and how many turns it has if a current of 1 A flows through it. Transformation ratio k = 4. What current flows throu - Cube-shaped box

The cube-shaped box is filled to the brim with 2 liters of milk. Calculate the edge and surface of the box. - Concrete column

The concrete column of the highway bridge has the shape of a block with dimensions of 1m x 0.8m x 25m. It should be lifted by crane to a height of 20m. What is the power of his engine if the lifting takes 2 minutes? - 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. - Energy consumption

The device is connected to 230V and draws 3.5A current. Power consumption is 1932kJ. How many minutes has this device been in operation? - Cardboard box

Peter had square cardboard. The length of the pages was an integer in decimetres. He cut four squares with a side of 3 dm from the corners and made a box out of it, which fit exactly 108 cubes with an edge 1 dm long. Julia cut four squares with a side of - Wall thickness

The hollow metal ball has an outside diameter of 40 cm. Determine the wall thickness if the weight is 25 kg and the metal density is 8.45 g/cm³. - 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. - Friction coefficient

What is the weight of a car when it moves on a horizontal road at a speed of v = 50 km/h at engine power P = 7 kW? The friction coefficient is 0.07 - Power input

The construction lift lifted a load weighing 300 kg to a height of 12 m with a uniform movement. How long has it taken for the load to be lifted if the efficiency is 75% and the engine has a power input of 5 kW? - A tile

A tile setter is covering 5ft by 5ft square shower wall. Each tile covers 4 5/8in by 4 5/8in square. How many rows of tile are needed to reach 5ft? How many tiles are needed to cover 5ft by 5ft square - Helmet

Nowadays cycling better results could be obtained not only due to rider physical preparation but also thanks to using updated technologies. One of the essential parts of the rider´s equipment is his or her helmet. While most bikers wear a helmet mainly to - 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 pow - A car

A car weighing 1.05 tonnes driving at the maximum allowed speed in the village (50 km/h) hit a solid concrete bulkhead. Calculate height would have to fall on the concrete surface to make the impact intensity the same as in the first case! - Cylindrical tank 2

If a cylindrical tank with volume is used 12320cm raised to the power of 3 and base 28cm is used to store water. How many liters of water can it hold? - Seawater

Seawater has a density of 1025 kg/m^{3}, ice 920 kg/m³. 8 liters of seawater froze and created a cube. Calculate the size of the cube edge. - The appliance

The appliance has a power input of 2.3 kW and is connected to the mains voltage of 230 V. What is the current flowing through the appliance? - Job task

After two hours and 40 minutes, the job is finished. Compared to last year, we were 40 minutes faster. What is the percentage increase to our performance?

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Unit conversion - practice problems. Third power - practice problems.