Mass + power - practice problems - page 2 of 3
Number of problems found: 44
- Transformer 20073
The transformer is oil-cooled and transforms a power of 20MW with an efficiency of 92%. Determine the temperature of the oil at the outlet of the transformer if the oil was 20°C when it entered the transformer. 2.5 liters of oil will flow through the tran - 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. - Material 16923
The cube weighs 32 kg. How much kg does a cube made of the same material, which has an edge four times shorter, weigh? - 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? - Performance 7737
Zdenek, weighing 54 kg, made 15 push-ups on the crossbar. The height he reached was about 40 cm. What kind of work did he do? What was his performance if the whole exercise took him a minute and a half? - Temperature 7595
Colorless liquid weighing m = 200 g is heated with constant stirring on a stove with power input P0 = 600W. 80% of the supplied energy is used to heat the liquid. Selected measured values of liquid temperature as a function of time are recorded in the t - 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 m3/s is supplied with a flow rate of h = 70.5 m at full power. a) What is the total installed pow - Confectionery 7318
The confectioner needs to carve a cone-shaped decoration from a ball-shaped confectionery mass with a radius of 25 cm. Find the radius of the base of the ornament a (and the height h). He uses as much material as possible is used to make the ornament.
- 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! - No smoke
Tobacco company NO-SMOKE adorned its stand at the cigarette-type trade fair with cigarette-shaped. The dimensions of which were 20 times the size of a regular cigarette. Regular cigarette contains 0.8 mg of nicotine. How much nicotine would a giant cigare - Consumption 6581
We heated water weighing 1 kg at 70 degrees in a kettle. C. In 5 min. What is the power consumption of the kettle? We do not take into account losses or boiling points. - Density 2
The driftwood has a mass of 25 grams and a volume is 30 cm to the 3rd power. What is the density of a piece of driftwood? And how do I figure it out? - Received 5578
Four boys passed the paper to harvest. John received 111 1/3 ducats, Michal 228 3/4, Peter 195 1/2 ducats, and Robert 146 1/4 ducats. How many kg of paper did each boy bring if they bought paper at 2.50 ducats per kg?
- Tower model
The tower's height is 300 meters, and its weight is 8000 tons. How high is the model of the tower's weight of 1 kg? (State the result in centimeters). The model is made from exactly the same material as the original no numbers need to be rounded. A result - Granite cube
What is the weight of a kilogram granite cube with an edge of 0.5 m if 1dm³ of granite weight 2600 g? - Hollow sphere
The steel hollow sphere floats on the water plunged into half its volume. Determine the outer radius of the sphere and wall thickness, if you know that the weight of the sphere is 0.5 kg and the density of steel is 7850 kg/m³ - BMI index
Calculate BMI (body mass index, an index indicating obesity, overweight, normal weight, underweight) man weighing m = 102 kg and height h = 159 cm. The index is calculated according to the equation (formula): BMI = (m)/(h²) With the BMI index is possible - Iron sphere
Iron sphere has weight 100 kg and density ρ = 7600 kg/m³. Calculate the volume, surface, and diameter of the sphere.
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