Skip to main content
Physics

Return to Question

deleted 1 character in body
Source Link
Eli
Eli
  • 12.9k
  • 2
  • 11
  • 31

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$$\int _{a}^{b} {-F}{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?(I know that sometimes the direction is important,The positive and negative here refer to the positive and negative in the same direction)

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?(I know that sometimes the direction is important,The positive and negative here refer to the positive and negative in the same direction)

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?(I know that sometimes the direction is important,The positive and negative here refer to the positive and negative in the same direction)

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

added 138 characters in body
Source Link
能够可能
能够可能
  • 35
  • 7

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?(I know that sometimes the direction is important,The positive and negative here refer to the positive and negative in the same direction)

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?(I know that sometimes the direction is important,The positive and negative here refer to the positive and negative in the same direction)

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

added 184 characters in body
Source Link
能够可能
能够可能
  • 35
  • 7

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

I know this is a very simple question, and I have searched it too. How to avoid incorrect symbols in calculation results.I don’t understand how to choose the sign of $ds$.

An object moves from a to b,Note the number $b<a$,$W>0$.

enter image description here Take the direction of $i$ as the positive direction,Can I think of $\vec{ds}$ as $\vec{b}-\vec{a}$?

$\int _{a}^{b} {-F}-{ds}=W<0$

I know that the choice of ab determines the positive and negative, maybe I should write $\int _{a}^{b} {-F}{ds}=w>0$

BUT enter image description here I changed the direction of i

Write the formula $\int _{a}^{b} {F}{ds}=W<0$

I can judge the positive or negative of the result by the order of the upper and lower limits of the integral and the sign of F. If it does not match, I will take the opposite sign for ds.I don’t want to judge and correct by the prediction result.

I can only modify the direction of ds through the results. It seems that this does not refer to the direction. Does it make sense to take positive and negative directions for ds?

How do I decide the sign of $ds$?Do I made any errors about the vector of ab and ds?

added 6 characters in body
Source Link
能够可能
能够可能
  • 35
  • 7
edited title
Link
Qmechanic ♦
Qmechanic ♦
  • 213.1k
  • 48
  • 590
  • 2.3k
added 251 characters in body; edited tags
Source Link
能够可能
能够可能
  • 35
  • 7
edited tags
Link
Qmechanic ♦
Qmechanic ♦
  • 213.1k
  • 48
  • 590
  • 2.3k
Source Link
能够可能
能够可能
  • 35
  • 7