IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: tnas11 on January 11, 2011, 11:06:42 am
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Im re-sitting Edexcel Physics Unit 1 tomorrow!! Code: 6PH01
When do we use Force x Displacement and Average Force x Displacement in Work Done?
Work Done = Force x Displacement and Work Done = F. Average x Displacement
Average Force = Initial Force + Final Force / 2
Its question 21) (a) (ii) (the chest expander question), in "New Template Exemplar" pass paper >> http://www.scribd.com/doc/24557363/GCE-Physics-6PH01
after searching, i understood that we use Average Force when the Force is not constant.. is this right?
so in all springs we use average force?
and what other situations do we use average force?
Exam is tomorrow, good luck to all!! :D
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Your link is broken.
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30 J ?
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no its 75J
this is how they solved it, i know how to solve it but i dont get why they used F. Average?
Work Done= F. Avg x Displacement
= 60*5/2 x 0.5
= 75 Joules
My question is when to use Average Force and when to use Force?
i think that average is used when the force is not constant as i found on the internet, but i want someone to tell me this is correct
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to be honest my teacher is ALWAYS telling us that Work done in a Wire *as in Strain Energy* is measured as follows ;
Work done = 0.5*force*extension.
When to use this ,is whenever they ask your for Work Done in a material that has elastic potential energy in it *in this case Spring*.
Hence,
Work done = 0.5 *force * extension * 5 blue ; cuz there are FIVE springs ;)
= 0.5 *(60) * ( 0.5) * 5
= 0.5 * (30) * (5)
= 0.5 * 150
= 75 J
good luck to u too ;)
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if you have any further Doubts please post over here :
https://studentforums.biz/sciences-149/edexcel-physics-doubts/msg387274/#msg387274
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oh yeah!!!! like the area under the force-extension graph = work done!
Area under graph = work done = 1/2 x force x extension!!!
thanks that made me connect the ideas together! :D
no but Work Done = Force x Distance!
and as you said
Power = Work Done/Time
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I removed the Post Since I noticed it was displacement NOT velocity *my bad *
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yeah no problem.. but thats for reminding me to connect both ideas :D
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Your Welcome :)