Power
Physics ⇒ Mechanics
Power starts at 8 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Power.
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When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 9
A 100 W light bulb is left on for 2 hours. How much energy does it use in joules?
A 1200 W microwave runs for 3 minutes. How much energy does it use in kilojoules?
A 40 W device is used for 30 minutes. How much energy does it use in joules?
A 60 kg person runs up a 5 m high hill in 10 seconds. What is the average power output? (Take g = 10 m/s²)
A car engine does 5000 J of work in 25 seconds. What is the power output of the engine?
A force of 10 N moves an object 5 m in 2 seconds. What is the power delivered?
A machine does 200 J of work in 10 seconds. What is its power output?
A motor lifts a 100 kg mass vertically upward at a constant speed of 2 m/s. What is the power output of the motor? (Take g = 9.8 m/s²)
A pump raises 500 liters of water per minute to a height of 10 m. What is the power required? (Take 1 liter = 1 kg, g = 10 m/s²)
A student climbs a staircase of 3 m height in 6 seconds. If the student's weight is 600 N, calculate the power developed.
Describe a real-life example where high power is needed but not necessarily a large amount of work.
Describe how you would measure the power output of a person climbing stairs.
Explain the difference between work and power.
Explain why power is important in designing machines and engines.
Explain why two machines with the same power rating might perform differently in practice.
If a 75 W fan runs for 8 hours, how much energy does it consume in kilojoules?
If a machine has a power rating of 250 W, how much work can it do in 4 seconds?
If a person lifts a 50 N box to a height of 2 m in 5 seconds, what is the power used?
If two people do the same amount of work but one does it in half the time, who has the greater power?
What is the SI unit of power?
