- #1

Pawn

- 18

- 3

- Homework Statement:
- The 38 problem:The result on the book is 10.6cm i keep getting 3.75

- Relevant Equations:
- X(t)=A×cos(w×t)

Last edited:

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- Thread starter Pawn
- Start date

- #1

Pawn

- 18

- 3

- Homework Statement:
- The 38 problem:The result on the book is 10.6cm i keep getting 3.75

- Relevant Equations:
- X(t)=A×cos(w×t)

Last edited:

- #2

- 12,025

- 5,058

Please show your work so that we can figure out where you went astray.

- #3

Pawn

- 18

- 3

Please show your work so that we can figure out where you went astray.

Please show your work so that we can figure out where you went astray.

- #4

- #5

- 12,025

- 5,058

And yes, please learn how to write equations in LaTeX. Meanwhile, please do no post pictures sideways.

- #6

DaveC426913

Gold Member

- 21,051

- 4,419

(This is intended to inspire a sanity check. If you mentally draw this motion in your head, that may help you figure out where you're going wrong.)

- #7

Pawn

- 18

- 3

The only other equation i have is the one for the velocity in an instant of time v(t)=-vmax × sin(w × t).

And yes, please learn how to write equations in LaTeX. Meanwhile, please do no post pictures sideways.

W-omega

And i dont know what LaTeX is.

- #8

Pawn

- 18

- 3

3.75*

(This is intended to inspire a sanity check. If you mentally draw this motion in your head, that may help you figure out where you're going wrong.)

- #9

DaveC426913

Gold Member

- 21,051

- 4,419

mm OK. Your notes say 3.75, though your problem statement says 37.5.3.75*

Not sure if you can still edit post #1.

- #10

- 12,025

- 5,058

If your textbook really does not have an expression for the position as a function of time, look it up on the web.The only other equation i have is the one for the velocity in an instant of time v(t)=-vmax × sin(w × t).

W-omega

And i dont know what LaTeX is.

To find how to use LaTeX to write and post equations, go here

https://www.physicsforums.com/help/latexhelp/

or click the link LaTeX Guide, lower left corner.

- #11

Pawn

- 18

- 3

Do you have any idea on how to solve it?If your textbook really does not have an expression for the position as a function of time, look it up on the web.

To find how to use LaTeX to write and post equations, go here

https://www.physicsforums.com/help/latexhelp/

or click the link LaTeX Guide, lower left corner.

- #12

hutchphd

Science Advisor

Homework Helper

- 4,975

- 4,145

- #13

Pawn

- 18

- 3

How ?

- #14

hutchphd

Science Advisor

Homework Helper

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Look in your book for the relation between T and ω. Tell me what it is

- #15

Pawn

- 18

- 3

ω=2π/TLook in your book for the relation between T and ω. Tell me what it is

- #16

hutchphd

Science Advisor

Homework Helper

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So in your equation for x $$x(t)=A\cos\frac {2\pi t} T $$ Now what is A?

- #17

Pawn

- 18

- 3

A is 15cm. Right?

- #18

hutchphd

Science Advisor

Homework Helper

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so t/T is 1/8 for t=0.1s

- #19

Pawn

- 18

- 3

But if we substitute the values we dont get the result that is in the book.So in your equation for x $$x(t)=A\cos\frac {2\pi t} T $$ Now what is A?

- #20

- #21

hutchphd

Science Advisor

Homework Helper

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cos (pi/4)= ? ( thats 45deg)

- #22

Pawn

- 18

- 3

Do we substitute pi with the value 3.14cos (pi/4)= ?

- #23

hutchphd

Science Advisor

Homework Helper

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You prefer 2pi/8 ??? see #18

- #24

Pawn

- 18

- 3

No sorry i didnt realise itYou prefer 2pi/8 ??? see #18

- #25

Pawn

- 18

- 3

0.70cos (pi/4)= ? ( thats 45deg)

- #26

hutchphd

Science Advisor

Homework Helper

- 4,975

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So are you good? I gotta go right now but let me know

- #27

Pawn

- 18

- 3

Yes thank you so much for helping me .So are you good? I gotta go right now but let me know

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