Fundamentals of Physics + power - practice problems
Number of problems found: 23
- 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
- Free fall
The elevator car weighing 720 kg is torn off at a height of 125 m and begins to fall in a free fall. How much kinetic energy does the elevator car have when it hits the ground floor of the building, when the free fall of the car lasted 5 s?
- Circuit voltage
Calculate the closed-circuit voltage. Calculate the power on the resistors. R1 = 30 ohms, R2 = 10 ohms. I = 0.1A. U =?. The resistors are connected in series, one after the other.
- Electric cooker
During which time t does an electric cooker with power input P = 500 W and with 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-1. K-1
- 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.
- 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.
- 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?
- 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
- 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!
Seawater has a density of 1025 kg/m3, ice 920 kg/m³. 8 liters of seawater froze and created a cube. Calculate the size of the cube edge.
- Resistance - ohms
If the resistance of the first resistor is 300 ohms and the resistance of the second resistor is 100 ohms. What is the resulting resistance?
- 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?
- Tower model
Tower height is 300 meters, weight 8000 tons. How high is the model of the tower's weight of 1 kg? (State the result in the centimeters). The model is made from exactly the same material as the original no numbers need to be rounded. A result is a three-d
What is the power output of a kettle 2 kW with an efficiency of 90%?
- 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 = 71 kg and height h = 170 cm. The index is calculated according to equation (formula): BMI = (m)/(h2) With BMI index is possibl
In homes with more floor elevators are used. For passenger transport, the most commonly used traction elevator counterweight. The top of the shaft engine room with the engine. The car is suspended on a rope, which is guided up over two pulleys to the coun
Fundamentals of Physics - practice problems. Power - practice problems.