Energy - math problems
Number of problems found: 56
- Positional energy
What velocity in km/h must a body weighing 60 kg have for its kinetic energy to be the same as its positional energy at the height 50 m?
Convert 660 m3 of natural gas volume to energy units kWh. Combustion of 1 cubic meter of natural gas is released energy 10.55 kWh.
In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a standard deviation of of 218 kWh. Find the consumption level separating the bottom 45% from the top 55%.
- 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?
- Harmonic oscillator
Calculate the total energy of a body performing a harmonic oscillating motion if its mass is 200 g, the amplitude of the deflection is 2 cm and the frequency is 5 Hz. Round the result to 3 decimal places.
- Energy saving
They were released three different, independent inventions saving 20%, 24% and 15% energy. Some considered that while the use of these inventions, the total savings will be 20% + 24% + 15% = 59%. Is this true? How much percent of energy will save all thre
- Electric energy
There are 875 identical light bulbs in the sports hall lighting for 2 hours. How long does the same amount of electricity consume 100 such bulbs?
- The elevator
The elevator car weighing 400 kg rises from the third to the fifth floor. By what value will the potential gravitational energy of the cabin increase? What useful work will the elevator motor do? The height of one floor is 5m .
- 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 power of the p
- Gasoline price
At 34.4 cents per liter, how much will 42 liters of gasoline cost?
- Slices of ham
If 17 slices equals 70 calories how many calories are in 5 slices?
A 60 W bulb consumes 0.12 kWh of electricity. How long did she stand light without a break?
A circuit has an input power of 58 mW. Its output power is 6 mW. What is the loss in decibels?
What is the power output of kettle 2 kW with efficiency 90%?
Locomotive pulled a train permanent load of 200 kN horizontally along the track of 5km. What work it done?
749 calories in a 7 - ounce serving . What is the unit rate?
252 miles a week fills up twice a week. Each fill is 38 gallons. What is gas mileage of the car?
- The bulb
Calculate what voltage is at the terminals of the bulb, if the work is done 18 J to transfer particles with an electric charge of 6 C.
Shot with a mass 43 g flying at 256 m/s penetrates into the wood to a depth 25 cm. What is the average force of resistance of wood?
20 cows has food for 60 days. We reduce the dose to two-thirds for 18 cows. How many days will be fed?