3.5 Power

• The units of power are watts.
• What is the formula for power in terms of work and time?

  $P =$$\frac{W}{t}$
• Match the concept with its definition:

  Energy ↔️ Capacity to do work

  Work ↔️ Transfer of energy

  Power ↔️ Rate at which work is done
• If a machine does 500 joules of work in 10 seconds, its power is 50 watts.


  True
• One watt is equal to one joule per second.
• What is the power of a machine that does 500 joules of work in 10 seconds?

  50 watts
• Power is measured in watts.
• One watt is equal to one joule per second.
• What is the power exerted when lifting a 20 kg box to a height of 1.5 meters in 5 seconds?

  58.8 watts
• What is the definition of work?

  Energy transfer due to force
• What is the unit of work?

  Joules
• What does work measure?

  Energy transfer
• What is the formula for power?

  $P =$$\frac{W}{t}$
• Match the feature with the correct concept:

  Work ↔️ Energy transfer

  Power ↔️ Rate of energy transfer
• Work measures the energy transferred, while power measures how quickly that energy is transferred.


  True
• The unit of power, the watt, is defined as one joule per second
• What is the relationship between watts, joules, and seconds?

  $1\, \text{W} =$$1\, \frac{\text{J}}{\text{s}}$
• Match the concept with its definition:

  Energy ↔️ Capacity to do work

  Work ↔️ Transfer of energy

  Power ↔️ Rate at which work is done
• Power is defined as the rate at which work is done or energy is transferred
• What is the formula for power in terms of work and time?

  $P =$$\frac{W}{t}$
• What is the unit equivalent to 1 watt?

  1 J/s
• Power measures the rate of energy transfer
• One watt is defined as one joule per second.


  True
• What is the relationship between watts, joules, and seconds?

  $1\, \text{W} =$$1\, \frac{\text{J}}{\text{s}}$
• What is the formula for power in terms of work and time?

  $P =$$\frac{W}{t}$
• What is the formula for instantaneous power?

  P_{\text{inst}} = \frac{dW}{dt}</latex>
• Instantaneous power is measured at a single point in time.

  True
• What is the formula for average power?

  $P_{\text{avg}} =$$\frac{W}{t}$
• Average power is the total work done divided by the total time taken.


  True
• The unit of power is the watt
• What is the definition of power?

  Rate of work done
• The formula for power is $P =$$\frac{W}{t}$.


  True
• The formula for power is $P =$$\frac{W}{t}$.


  True
• What is the power of a machine that does 500 joules of work in 10 seconds?

  50 watts
• What is the power of a machine that does 500 joules of work in 10 seconds?

  50 watts
• Work measures energy transfer, while power measures the rate of energy transfer.

  True
• Work is measured in joules.
• The formula for work is W = Fd \cos(\theta)</latex>
• What three factors does work depend on?

  Force, distance, angle
• What is the unit of power?

  Watts