Edexcel - M3 - 18th May 2016

Am I right in assuming that maximum tension in a vertical circle occurs at the bottom? And minimum at the top providing the string does not go slack before it reaches there? Does this then mean that the max speed is at the bottom and the min is at the top too?

Reply 625

Original post by paradoxequation

Am I right in assuming that maximum tension in a vertical circle occurs at the bottom? And minimum at the top providing the string does not go slack before it reaches there? Does this then mean that the max speed is at the bottom and the min is at the top too?

Yep all of that is true.
Can be seen easily by Enrgy considerations at top and bottom.

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Reply 626

Any hard qs then not got much left to do now

Reply 627

Ayman!

Original post by alvosm

hi, im new to the thread :tongue:

. i was wondering if anyone could explain me part b)

If it returns to the upright position, what can you say about where the COM lies?

Original post by BBeyond

Any hard qs then not got much left to do now

Done with everything, fam? Same here

Reply 628

Original post by Ayman!

If it returns to the upright position, what can you say about where the COM lies?

Done with everything, fam? Same here

Yh done all past papers from like 09 onwards now with a couple from before

Reply 629

samb1234

13

Original post by BBeyond

Any hard qs then not got much left to do now

Do some questions by topic from pamt for the topics you are worst at- even if you know everything chances are there are still topics you are more likely to screw up somewhere

Reply 630

paradoxequation

Original post by physicsmaths

Yep all of that is true.
Can be seen easily by Enrgy considerations at top and bottom.

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Cool. So in which situations do we say that the min tension occurs when v=0? Do we say this when we have vertical motion where we don't know if it will complete a full circle? I hope my question was clear lol.

Reply 631

Original post by samb1234

Do some questions by topic from pamt for the topics you are worst at- even if you know everything chances are there are still topics you are more likely to screw up somewhere

What papers r they from.

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Reply 632

samb1234

13

Original post by physicsmaths

What papers r they from.

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I believe they are all from edexcel papers not sure how old they are though so chwnces are if youve done a lot of papers you will have done quite a few of them. Still it doesn't matter that much really good to refresh techniques for things you din't like

Reply 633

Original post by paradoxequation

Cool. So in which situations do we say that the min tension occurs when v=0? Do we say this when we have vertical motion where we don't know if it will complete a full circle? I hope my question was clear lol.

Na I don't understand what your saying. When v is zero in a circular motion it would just drop out of motion.

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Reply 634

Original post by physicsmaths

Na I don't understand what your saying. When v is zero in a circular motion it would just drop out of motion.

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Jan 10 q 5b you have to use MIn T occurs when v =0

Reply 635

Original post by BBeyond

Jan 10 q 5b you have to use MIn T occurs when v =0

Lemme have a look at that actually cause i don't understand what hes asking.

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Reply 636

paradoxequation

Original post by BBeyond

Jan 10 q 5b you have to use MIn T occurs when v =0

Yeah, that was the one that got me thinking bout this. I tried to set theta to 270 degrees so that P would be at the top but I got a negative answer which confused me.

Reply 637

Original post by BBeyond

Jan 10 q 5b you have to use MIn T occurs when v =0

Lemme have a look at that actually cause i don't understand what hes asking. After looking at it this just looking at sin function.

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Reply 638

Original post by physicsmaths

Lemme have a look at that actually cause i don't understand what hes asking. After looking at it this just looking at sin function.

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The max part is but not the min?

Reply 639

J.M.Keynes