GCSE Physics - Power and Work Done #7

The video tutorial explains the concept of power, highlighting two definitions: power as the rate of energy transfer and power as the rate of work done. It clarifies the term 'work done' and distinguishes it from energy transfer. The tutorial includes examples comparing the power of two lamps and calculating energy transfer in a microwave. It also demonstrates how to calculate power when work is done, such as pushing a car. Key units like watts, joules, and kilojoules are discussed.

What are the two definitions of power discussed in the video?

• Power is the rate of energy transfer and the rate of work done.

• Power is the force applied and the time taken.

• Power is the amount of energy stored and the amount of work done.

• Power is the speed of an object and the distance it travels.

In the context of the video, what is 'work done'?

• The energy stored in a battery.

• The energy transferred when a force moves an object over a distance.

• The energy lost due to friction.

• The energy required to heat an object.

How do you determine which lamp is more powerful based on the video?

• By comparing the energy transferred over time for each lamp.

• By comparing the color of the lamps.

• By comparing the brightness of the lamps.

• By comparing the size of the lamps.

If a microwave operates at 1,100 watts for 3 minutes, how much energy is transferred?

• 198,000 joules

• 198 joules

• 19,800 joules

• 1,980 joules

What is the power used when 9 kilojoules of work is done in 20 seconds?

• 450 watts

• 225 watts

• 900 watts

• 600 watts