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## Homework Statement

i dont understand the statement 1 and 2 , can someone help to explain ?

for 1 , does the author mean Fh= Fv ??

for 2 , does the author mean Fv = Fh + W ? but in statement 1 , Fh already = Fv

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- Thread starter werson tan
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- #1

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i dont understand the statement 1 and 2 , can someone help to explain ?

for 1 , does the author mean Fh= Fv ??

for 2 , does the author mean Fv = Fh + W ? but in statement 1 , Fh already = Fv

- #2

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First the "horizontal projection" of the curved surface here means an imaginary horizontal surface found by projecting the curved surface down onto a horizontal plane passing through the lower edge of the curved surface. The force F

Similarly, F

The force acting on the curved surface is F, and this has horizontal and vertical conponents F

The text shows:

F

F

Which seems perfectly reasonable.

- #3

256bits

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Hi, werson tan.## Homework Statement

i dont understand the statement 1 and 2 , can someone help to explain ?

for 1 , does the author mean Fh= Fv ??

for 2 , does the author mean Fv = Fh + W ? but in statement 1 , Fh already = Fv

For 1, No he does not mean that Fh=Fv.

It is confusing by what the author means by "vertical projection of the curved surface."

The author himself does not explain it very well , so I do attribute some of fault of understanding to his in not referencing what he does actually means with the terms a vertical projection and horizontal projection.

( He is using the orientation of the plane for describing the projection rather than the direction of projecting the surface onto a plane. If he would have said "a projection onto a vertical plane" or "a projection onto a horizontal plane" it might have been more clear. )

If you take a look at Fig. 3-33, the vertical line where Fx is acting is the "vertical projection of the curved surface."

For the author, a vertical projection to him is,

- looking at the curved surface in the horizontal direction, the curved surface can be projected onto a vertical plane. This is where Fx acts.

Similarly, for the author, a horizontal projection is,

- looking at the curved surface in the vertical direction, the curved surface can be projected onto a horizontal plane. This is where Fy acts.

Hope that helps.

For some reason the connection terminated to PF around 0300hrs before I could post, so haruspex beat me in answereing.

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