685 reputation
59
bio website
location United Kingdom
age
visits member for 2 years
seen Nov 18 at 16:54

Maths teacher, Hobby programmer, ex Computing teacher.

I'm old enough that my early internet experience was using a dumb terminal with bakelite keys to access a server in a different city via JANet.

Some symbols I might want which aren't available on my phone: `` ⊥ |


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awarded  Yearling
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24
awarded  Autobiographer
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suggested rejected edit on Why is filling a balloon from your mouth much harder initially?
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awarded  Yearling
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awarded  Guru
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awarded  Constituent
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awarded  Caucus
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awarded  Good Answer
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comment With Newton's third law, why are things capable of moving?
A nice exercise is to draw the table, matchbox, person and earth and find as many third law matched pairs you can (remember to make sure they're acting on different objects). There's an answer to be found in the revision history of my answer (click the link after the word edited), but I hid it because I feel it distracts from the main part of the answer.
Dec
2
revised With Newton's third law, why are things capable of moving?
The additional diagram didn't add anything, and I felt it was distracting from the main point.
Dec
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comment With Newton's third law, why are things capable of moving?
@JavierBadia Fixed now. Thanks for pointing out my silly (and ironic) but key mistake. My answer is better now because of your comment.
Dec
2
revised With Newton's third law, why are things capable of moving?
better diagram correcting silly error, additional over-the-top diagram for fun
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awarded  Mortarboard
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awarded  Critic
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comment With Newton's third law, why are things capable of moving?
@StevenLu because I found it funny, particularly "May cause fire.".
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2
revised With Newton's third law, why are things capable of moving?
blue forces are equal by first law!
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awarded  Nice Answer
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answered With Newton's third law, why are things capable of moving?
Nov
30
comment Why is a book on a table not an example of Newton's third law?
The weight of the book does not act on the table, it acts on the earth and the book. The force on the table due to the book is a normal force, not a weight force, (just as the force on the book due to the table is not, as you say). Neither of these reaction forces are directly due to gravity, both of them are equal to the weight of the book only because of equilibrium; saying one is and the other isn't isn't true, and these normal forces can never be different to each other precisely because of Newton's third law.
Nov
29
answered How do I know the position of some mass in space (starting at rest) over time when applying earth's gravitational force to it?