Energy - practice for 13 year olds - page 2 of 6
Number of problems found: 101
- Resistance 80703
An immersion cooker has a resistance of 30 ohms and is connected to a voltage of 120 V. How much heat is generated in 2 hours? - Calculate 80550
A cheetah weighing 38 kg moves at a speed of 108 km/h. Calculate its kinetic energy - Electrical 80549
The factory hall is lit by 76 light bulbs, each of which has an input of 200W. Determine how much electrical work will be saved annually if the light is on an average of 100 minutes less per day. Consider 260 business days. - Coefficient 80515
A tractor pulls a tree trunk weighing 1.5 t for a distance of 2 km along a horizontal road at a constant speed. What mechanical work does it do if the coefficient of sliding friction is 0.6?
- A box 5
A cereal box states that there are 90 Calories in a 3/4 - cup serving. How many Calories are there in 4 cups of cereal? - Kinetic energy
A 100 kg car has a velocity of 15 m/s. what is the car's kinetic energy? - A car 6
A car holds 15 liters of fuel. The car consumes 3 liters of fuel each 100 km. We started a trip of 350 km with a full tank of fuel. How much fuel remains in the tank at the end of the trip? - Which 10
Which will have greater momentum between a ten-wheeler truck weighing 7,000 kg and a bus that weighs 5,000kg if the bus is moving at 15 m/s while the truck is moving at 10 m/s? - Calculate 71684
Calculate the mass of water that gave off 520.5 kJ of heat when cooled from 69 °C to 27 °C.
- Increases 69454
The car weighs 1850 kg and increases its speed from 27 to 81 km/h. How much has its kinetic energy increased? - Pump power
Determine the pump power if: I pour 3 m³ of water from the tank in 120 seconds with a hose. The height of the hose mouth above the tank is 1.5 m. The water's speed from the hose outlet is 20 m/s. - Transfers 67414
At 80 cm above the road, a person transfers a stone weighing 2 kg parallel to it in a uniform motion along a path of 6 m in 10 s. With what power does it work? - Performance 66404
A person weighing 50 kg can climb 15 stairs. One step is 18 cm high. Determine a person's performance when: a) slowly climbing the stairs if it took him 13 seconds b) going down the stairs slowly if it took him 10 seconds c) quickly climbing the stairs if - Direction 63264
A railway car weighing 10 t moves around the Earth at a speed of 10 m/s. Determine the kinetic energy of the car relative to the Earth and relative to another car moving at a speed of 10 m relative to the Earth. s-1, both in the same direction and the opp
- Power consumption
The price of electricity is ₱6.50 per kilowatt hour (kWh). How much electricity was consumed if a television with 120 W power consumption ran from 7:30 AM to 12:30 PM? How much will this cost? - Gas prices 2021
According to the SPP price list in 2021, the price of natural gas, together with its supply, is as follows: D1 - we cook. Fix 3.34 euros/month and 0.0479 euros/kWh (1 cubic meter of gas is approximately 10.555 kWh. It is called combustion heat and changes - 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.
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