Power Physics Formulas, Examples, Questions and Answers

Power Physics

Power physics is is the amount of energy delivered or absorbed by an element in a given time (p = dW / dt). The unit in the International System is the watt, one joule per second.

Power can be described as the rate at which energy is produced or consumed: when an action requires energy, such as lifting a heavy object up a floor, this energy is the same whether the object is ascended slowly or quickly. There is however a physical difference, it is that climbing it quickly requires more power.

Formula power physics formula

p = dW / dt

where P is power, W is work, and t is time.

Derivations from other quantities

P = E/t (Power = Energy / Time)

P = F v (Power = Force . Velocity)

P = V I (Power = Volt . Current)

P = τ ω (Power = Torque . Angular velocity)

Read also: Physics Symbols and Chemical | Meanings and Explanations

How to find a power?

There are several calculations that can be used to find a power. These are for example:

  1. multiply a force by a speed: pulling a rope with a force of 10 newtons and at two meters per second represents a power of 20 watts.
  2. in electricity, multiplying an electrical intensity by an electrical voltage.
  3. by division, we can find an average power by dividing an energy by a time. For example, if logs of wood weighing about two kilograms each represent an energy of 30,000,000 joules, and one is added per hour (3,600 seconds) to a fire, this fire has an average power of 30,000,000 / 3,600 = 8,333 W or 8.3 kilowatts.


Calculate the work if, Power = 30 , Time = 10 , Work = ?

Formula: Work = Power x Time
Steps: Putting values
= 30 x 10
= 300 j

Calculate the time, if, Power = 50 , Time = , Work = 500

Formula: Time = Work/Power
Steps: Putting values
= 500/50
= 10 N

Calculate the power. Power = , Time = 50 , Work = 350

Formula: Power = Work/Time
Steps:  Putting values

= 350/50
= m


Learn More →

Leave a Reply

Your email address will not be published. Required fields are marked *