Energy - practice problems - page 5 of 10
Number of problems found: 181
- The bath
Dad poured 50 liters of water at 60°C into the tub. How much cold water must he add at 10°C to obtain a bath that has a temperature of 40°C? - Constant 36941
The truck travels at a constant speed of 70 km/h. The first time it goes empty, and the second time it comes with a load. In which case is its kinetic energy smaller? - Suitcase's 36531
What was the suitcase's weight if I lifted it to a height of 150cm and did the work 0.5kJ? - Stroller 36521
Mom did a 5kJ job pushing the stroller. She always pushed him on the plane with a force of 50N. How far did she push the stroller?
- Weighing 36511
The crane lifted a concrete block weighing 3 tons to a height of 500 cm. What work did it do? - Constant 36313
The truck weighs 4.5 tons and is moving at a constant speed of 72 km/h. How big is his kinetic energy? - Electric cooker
During which time does an electric cooker with power input P = 500 W and efficiency n = 75% heat water with mass m = 2 kg and temperature t1 = 10°C to the boiling point (t2 = 100°C)? The specific heat capacity of water is c = 4 180 J/kg/K. - Harmonic oscillator
Calculate the total energy of a body performing a harmonic oscillating motion if its mass is 200 g, the deflection amplitude is 2 cm, and the frequency is 5 Hz. Please round the result to 3 decimal places. - Concrete column
The concrete column of the highway bridge has the shape of a block with dimensions of 1m x 0.8m x 25m. Crane should lift it to a height of 20m. What is the power of his engine if the lifting takes 2 minutes?
- Receiving heat
How many degrees Celsius was an iron cylinder weighing 300 g heated in a water bath if it received heat of 7.2 kJ? (specific heat capacity of iron c = 0.46kJ/kg/ºC) - 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. - Inclined plane
1. How much work W do we have to do to pull a body weighing 200 kg along an inclined plane with a length of 4 m to a total height of 1.5 m? 2. Find the force we need to exert to do this if we neglect frictional resistance. 3. Find the force we would need - Water mixing
We have 520 ml of hot water and 640 ml of water at 48°C. What is the temperature of approximately hot water when the resulting mixture has a temperature of 65°C? - 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.
- Resistance 25021
Calculate the resistance and power of the appliance through which a current of 20mA flows at the mains voltage (230 V). - The coal
The coal stock would be enough to heat a larger room for 12 weeks and a smaller one for 18 weeks. It was heated for four weeks in both rooms, then only in the smaller one. Thus, the coal stock was enough for how long? - Energy consumption
The device is connected to 230V and draws a 3.5A current. Power consumption is 1932kJ. How many minutes has this device been in operation? - Movement 21953
We lift a box weighing 50 kg onto a railway wagon with precise movement along a 3m track. We will use a fixed pulley. What is the pulling force on the free end of the rope? - Cooker
A current of 2A passes through the immersion cooker at a voltage of 230V. What work do the electric field forces do in 2 minutes?
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 tranDo you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
