Energy + fundamentals of Physics - practice problems - page 3 of 6
Number of problems found: 117
- Ice to boiling water
Calculate the heat needed to convert 5kg of ice at a temperature of -5°C to water with a temperature of 100°C. c (water) = 4200 J/°C/kg, c (ice) = 2100 J/°C/kg. The mass group heat of solidification of water is l = 334 kJ/kg. Calculate the heat that 1k g - Lead melt
Find the heat needed to melt an object made of lead weighing 250g and an initial temperature of 35°C. Lead melts at 327°C at normal pressure. Mass heat capacity of lead c = 129 J/kg • K and mass latent heat of lead lt (t is the subscript) = 22.6 kJ/kg. - What power
What power should the radiator have in a room 5x4 meters with a height of 3 meters? Hint: Calculate 35 watts per meter³ when 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 help you. - There
There is 5 l of water with a temperature of 20°C in the bucket. We add 3 liters of hot water. The resulting temperature will be 30°C. What was the temperature of the hot water?
- Thermometer
Immerse a thermometer with a heat capacity of 2.0 J. K-1 in water weighing 67.0 grams. Before water immersion, the thermometer showed a temperature of 17.8 degrees Celsius. After reaching equilibrium, the temperature is 32.4 degrees. What was the water te - Flatbed 47151
How many bricks do they have to lift on a 1.2 m high flatbed if I want to do the work 5.88kj and one brick weighs 5 kg? - Latent heat
How much heat is needed to take from 100 g of water at 20°C to cool to the ice at -18°C? Mass heat capacity c (ice) = 21kJ/kg/°C; c (water) = 4.19 KJ/kg/°C and the mass group heat of solidification of water is l = 334kJ/kg - Designated 44741
Cathedral height 110m, sphere weight 6000kg, dome diameter 43m, crane arm length 25m a) what was the diameter of this sphere? b) how much mechanical work had to be done to lift it to the designated place? - Consumption 44071
Calculate the electric motor's power if it works for 10 minutes, and the electricity meter measured the consumption of 500 Wh.
- Movement 43831
The crane motor has a constant power of 9 kW. How long does it take to lift a body weighing 12 tons to a height of 9 m with constant movement? - Mechanical 43721
A body weighing 2 kg falls from a height of 45 m in a free fall. What will be its potential energy and total mechanical energy after 2 s from the beginning of the movement? - The aluminum
We placed the aluminum object with a weight of 0.80 kg and a temperature of 250°C in the water with a weight of 1.6 kg and a temperature of 23°C. What is the system temperature after reaching equilibrium? We assume that the heat exchange occurred only bet - The bath
The bath has water with a volume of 220 l and a temperature of 65°C. Find the mass m2 of water at 15°C to be poured, so the resulting temperature in the bath will be 40°C. We neglect the heat exchange between water and the environment. The mass - Potential 42561
The elevator cabin weighing 720 kg goes from the ground floor to the top floor of the building, at 125 m. How much potential energy does the elevator cabin have on the top floor of the building - at the height of 125 m?
- Radiators
Calculate the radiator output if it has a thermal gradient (difference between inlet water and return temperatures) a) 5°C b) 10°C c) 15°C d) 20°C A heating water volume flow is 45 kg/h. How fast the water flows from the supply pipe to the radiator e) DN1 - Free fall
The elevator car weighing 720 kg, is torn off at the height of 125 m and begins to fall in a free fall. How much kinetic energy did the elevator car have when it hit the ground floor of the building when the free fall of the car lasted 5 s? - Performance 41891
The car's engine develops a power of 1800N. Find its performance if it travels evenly on a horizontal path at 48 km/h. - Gravitational 41861
Find the potential gravitational energy of a 2000kg tow cage relative to the bottom of an 850m deep draw pit when the cage is on the surface. - Travels 41851
The car, with a weight of 20 kN, travels at a speed of 54 km/h. What is its kinetic energy?
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