# Feynman lectures on physics

• Intro Physics
Gold Member
I was reading Motion chapter 8 in Vol 1 and I came across a line in speed topic which seemed confusing. So I checked with others and we concluded that its a mistake. Are there printing mistakes in this book? I will be surprised. Its pearson.

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Gold Member
Mentor
If you think "at the beginning of the 6th minute" is in error, what do you think it should be, instead?

As a guess, perhaps your confusion comes from the fact that the "n'th minute" begins at t = n-1 minutes and ends at t = n minutes.

pbuk
Gold Member
If you think "at the beginning of the 6th minute" is in error, what do you think it should be, instead?

As a guess, perhaps your confusion comes from the fact that the "n'th minute" begins at t = n-1 minutes and ends at t = n minutes.
Yes! It should be “at the beginning of the 7th”

weirdoguy and pbuk
Yes! It should be “at the beginning of the 7th”
Did you understand @jtbell 's comment? The 7th minute begins at t=6 and ends at t=7. This is because the first minute begins at t=0.

Mr.Husky, vanhees71 and pbuk
Gold Member
Did you understand @jtbell 's comment? The 7th minute begins at t=6 and ends at t=7. This is because the first minute begins at t=0.
Yeah! If it would be 6th then it would be from t=5 to t=6. But we have 5000ft traveled from t=6 to t=7 ie 7th minute not 6th minute.

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pbuk
Homework Helper
Gold Member
Yeah! If it would be 6th then it would be from t=5 to t=6. But we have 5000ft traveled from t=6 to t=7 ie 7th minute not 6th minute.
Yes you are right, he should have said "at the beginning of the 7th minute" or "at 6 minutes".

But this is completely irrelevant to the point Feynman is making: you should focus more on learning the point that is being made rather than finding immaterial faults in the teaching materials.

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DaveE
Gold Member
Yes you are right, he should have said "at the beginning of the 7th minute" or "at 6 minutes".

But this is completely irrelevant to the point Feynman is making: you should focus more on learning the point that is being made rather than finding immaterial faults in the teaching materials.
It is unacceptable and unimaginable that a book by such a great man could have errors.

Homework Helper
2022 Award
It is unacceptable and unimaginable that a book by such a great man could have errors.

RPF says:"we can get a rough idea that she was going 5000 ft/min during the 7th minute, but we do not know, at exactly the moment 7 minutes, whether she had been speeding up and the speed was 4900 ft/min at the beginning of the 6th minute, and is now 5100 ft/min"
Frankly I do not see anything incorrect in this nor do I care . But always remember (from RPF): "Science is the belief in the ignorance of experts"

pbuk, DaveE and Doc Al
Mentor
physical angler, pinball1970, TSny and 7 others
Gold Member
It is unacceptable and unimaginable that a book by such a great man could have errors.
You have VERY high standards for great men. Everyone makes mistakes. Everyone. Especially when the mistakes are of little importance, like this one.

physical angler, pinball1970, Delta2 and 4 others
Gold Member
It is unacceptable and unimaginable that a book by such a great man could have errors.
Maybe you are good in physics, but you don't know much about psychology.

Mr.Husky
codelieb
All books have errors, but few have people dedicated to correcting them.

Mike Gottlieb
Editor, The Feynman Lectures on Physics

vanhees71, hutchphd, pbuk and 2 others
Gold Member
2022 Award
It is unacceptable and unimaginable that a book by such a great man could have errors.
Have you ever written a scientific paper or lecture notes? If you tell all of us how to safely avoid any typos and mistakes, you'd be a hero!

Delta2
codelieb
Couldn't Feynman (and his coauthors) be using 0-based counting here, so that what you call "the first minute" he would call "the 0th minute," and what you call the seventh minute he calls the sixth? Zero-based counting is not uncommon in vernacular English. For example, when referring to the floors of a house, what some people call "the first floor" other's call "the second floor."

Gold Member
2022 Award
I wouldn't use the formulation "the n-th minute" at all. What is this good for? It only underlines why we use math to describe physics and describe motions of particles with help of vectors (position, velocity, acceleration) as function of time.

Gold Member
Have you ever written a scientific paper or lecture notes? If you tell all of us how to safely avoid any typos and mistakes, you'd be a hero!
Thanks for the hero to be!

Homework Helper
Gold Member
Couldn't Feynman (and his coauthors) be using 0-based counting here, so that what you call "the first minute" he would call "the 0th minute," and what you call the seventh minute he calls the sixth?
No, you can see that from the numbers. It is just an inconsequential slip - he probably just misread his notes or was ad-libbing. Or perhaps he did it deliberately to confuse people who can't see the wood for the trees.

codelieb
No, you can see that from the numbers. It is just an inconsequential slip - he probably just misread his notes or was ad-libbing. Or perhaps he did it deliberately to confuse people who can't see the wood for the trees.
Your supposition that Feynman would deliberately confuse people (his freshman students) is impertinent, and you are wrong not only about that. For example where it says "but something happened between 3 and 4 and even more so at 5," Feynman is referring to what rudransh verma would call the 4th, 5th and 6th minutes.

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vanhees71 and rudransh verma