**WORK****Add information to your notes & complete quizzes & label scores by quiz or activity name; turn into me!**

**In science, the word**

**"work"**has a particular meaning.

**Work**is done when amakes an object move.__force__**Work**is only done when the object moves

**Work = Force X Distance**

**W = F d**

**Work**is done when amoves an object or changes its**force**.**direction**- It is measured in
**Joules**.

- Rule for
**Work****Work (joules) = Force (newtons) × Distance (meters)**

- Example to calculate Work
**Question:**A weightlifter raises weights of 2000 newtons from the floor to a height of 2 meters. How much work has been done?**Answer:**

Work | = Force × Distance |

= 2000 N × 2 m | |

= 4000 J (joules) |

**MEASURING WORK**

work transfers energy from one object to another & like energy, is measured in joules (J).

One joule equials the work done (and energy transferred) when a force 1 newton (N) moves an object 1 meter in the direction of the force.

**Force = mass x acceleration**

**F = m x a**

If this man pushes the box with a force of 100 newtons for 3 meters, he performs _____?

**POWER**Power is the rate at which work is done, or energy is transferred. It is measured in watts (W), named after James Watt, and is worked out by dividing the work done by the time taken to do it.

# Power

**Power**is the rate at which work is done.**Power**is measured in**Watts**.

- Rule for Power

Power (watts) = | Work (joules) |

Time (seconds) |

- Example of calculating Power
**Question:**A weightlifter lifted 2000 newtons to a height of 2 meters. This was 4000 joules of work. What is the power output if this was done for 2 seconds?**Answer:**

Power = | Work | = | 4000 J | = 2000 W (watts) |

Time | 2 s |

It takes twice as much power to move the box 3 meters in one minute as to move it 3 meters in two minutes.

You can measure how much work you do (in joules) when you go upstairs by measuring the height of the stairs & multiplying it by our weight in newtons (your weight in kilograms x 10).

Divide the work you do by the time it takes to do it to find out how much pwer you exert (in watts). The quicker you go, the more power you exert.

**ACTIVITY I**

**ACTIVITY QUIZ**

**ACTIVITY II**

**ACTIVITY QUIZ II**

**ACTIVITY III**