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Work Done

258 bytes removed, 10:18, 9 October 2018

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==Key Stage 3==

===Meaning===

~~{{Infobox physical quantity~~

~~| bgcolour={pink}~~

~~| name = Work~~

~~| image = [[File:Baseball pitching motion 2004.jpg|250px]]~~

~~| caption = A [[baseball]] [[pitcher]] does positive work on the ball by applying a force to it over the distance it moves while in his grip.~~

~~| basequantities = 1 [[kilogram|kg]]⋅[[metre|m]]2⋅[[second|s]]−2~~

~~| unit = [[joule]] (J)~~

~~| otherunits = [[Foot-pound (energy)|Foot-pound]], [[Erg]]~~

~~| symbols = ''W''~~

~~| dimension = '''M''' '''L'''2 '''T'''−2~~

~~| derivations = ''W'' = '''[[force (physics)|F]]''' ⋅ '''[[Displacement (vector)|s]]''' ~~

~~''W'' = ''[[torque|τ]]'' ''[[angle|θ]]''~~

}}

[[Work Done]] is the amount of [[Energy Transfer|energy transferred]] by the action of a [[force]].

:<math> W = 48J</math>

: 2. The brakes on a car apply a force of 10,000N. The car travels a distance of 15m braking. Calculate the work done by the brakes.

: Force = 10,000N: Distance moved in the direction of the force = 15m:<math> W = Fd</math>:<math> W = 10,000 \times 15</math>:<math> W = 15,000J</math>

: 3. A person carries a 20N box along a horizontal path of 20m.

: Force = 40N

: Distance moved in the direction of the force = 0m

:<math> W = Fd</math>

:<math> W = 20 \times 0</math>

:<math> W = 0J</math>

No work has been done because the movement is not in the direction of the force. The weight acts downwards but the movement was horizontal.

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