Horizontal angular rotation speed











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Below is the question I'm not sure I've properly solved.



A smooth bead of mass 100g is threaded on a light inextensible string of length 70 cm. The string has one end attached to a fixed point A and the other to a fixed point B 50 cm vertically below A. The bead moves in a horizontal circle about the line AB with a constant angular speed of $omega$ rad/s, and the string taut. If the bead is at a point C on the string with AC = 40 cm, find the value of $omega$ and the tension in the string.



Because its a 3-4-5 triangle, I found the horizontal rotation plane to be 0.18m above B, and therefore 0.32m below A. The radius is then 0.24m. I found this by extending AC to 6.25m. I then resolve the vertical and horizontal forces and found $omega$ to be 4.88 rad/s. I`m however not sure about this answer as books says 16.9, 4.9N.



Any help would be appreciated.



Here is an image to help.



horizontal_rotation_plane






geometry trigonometry physics







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  • Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
    – maxmilgram
    22 hours ago










  • @maxmilgram, I hope that helps
    – tas75
    22 hours ago










  • I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
    – Phil H
    18 hours ago










  • See revised answer, same as the book.
    – Phil H
    14 hours ago










  • @Phil H, thanks for confirming the books answer
    – tas75
    13 hours ago















up vote
0
down vote

favorite












Below is the question I'm not sure I've properly solved.



A smooth bead of mass 100g is threaded on a light inextensible string of length 70 cm. The string has one end attached to a fixed point A and the other to a fixed point B 50 cm vertically below A. The bead moves in a horizontal circle about the line AB with a constant angular speed of $omega$ rad/s, and the string taut. If the bead is at a point C on the string with AC = 40 cm, find the value of $omega$ and the tension in the string.



Because its a 3-4-5 triangle, I found the horizontal rotation plane to be 0.18m above B, and therefore 0.32m below A. The radius is then 0.24m. I found this by extending AC to 6.25m. I then resolve the vertical and horizontal forces and found $omega$ to be 4.88 rad/s. I`m however not sure about this answer as books says 16.9, 4.9N.



Any help would be appreciated.



Here is an image to help.



horizontal_rotation_plane






geometry trigonometry physics







share|cite|improve this question
























  • Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
    – maxmilgram
    22 hours ago










  • @maxmilgram, I hope that helps
    – tas75
    22 hours ago










  • I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
    – Phil H
    18 hours ago










  • See revised answer, same as the book.
    – Phil H
    14 hours ago










  • @Phil H, thanks for confirming the books answer
    – tas75
    13 hours ago













up vote
0
down vote

favorite









up vote
0
down vote

favorite











Below is the question I'm not sure I've properly solved.



A smooth bead of mass 100g is threaded on a light inextensible string of length 70 cm. The string has one end attached to a fixed point A and the other to a fixed point B 50 cm vertically below A. The bead moves in a horizontal circle about the line AB with a constant angular speed of $omega$ rad/s, and the string taut. If the bead is at a point C on the string with AC = 40 cm, find the value of $omega$ and the tension in the string.



Because its a 3-4-5 triangle, I found the horizontal rotation plane to be 0.18m above B, and therefore 0.32m below A. The radius is then 0.24m. I found this by extending AC to 6.25m. I then resolve the vertical and horizontal forces and found $omega$ to be 4.88 rad/s. I`m however not sure about this answer as books says 16.9, 4.9N.



Any help would be appreciated.



Here is an image to help.



horizontal_rotation_plane






geometry trigonometry physics







share|cite|improve this question















Below is the question I'm not sure I've properly solved.



A smooth bead of mass 100g is threaded on a light inextensible string of length 70 cm. The string has one end attached to a fixed point A and the other to a fixed point B 50 cm vertically below A. The bead moves in a horizontal circle about the line AB with a constant angular speed of $omega$ rad/s, and the string taut. If the bead is at a point C on the string with AC = 40 cm, find the value of $omega$ and the tension in the string.



Because its a 3-4-5 triangle, I found the horizontal rotation plane to be 0.18m above B, and therefore 0.32m below A. The radius is then 0.24m. I found this by extending AC to 6.25m. I then resolve the vertical and horizontal forces and found $omega$ to be 4.88 rad/s. I`m however not sure about this answer as books says 16.9, 4.9N.



Any help would be appreciated.



Here is an image to help.



horizontal_rotation_plane






geometry trigonometry physics




geometry trigonometry physics






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited 18 hours ago









bob.sacamento

2,3821819




2,3821819










asked 22 hours ago









tas75

83




83












  • Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
    – maxmilgram
    22 hours ago










  • @maxmilgram, I hope that helps
    – tas75
    22 hours ago










  • I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
    – Phil H
    18 hours ago










  • See revised answer, same as the book.
    – Phil H
    14 hours ago










  • @Phil H, thanks for confirming the books answer
    – tas75
    13 hours ago


















  • Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
    – maxmilgram
    22 hours ago










  • @maxmilgram, I hope that helps
    – tas75
    22 hours ago










  • I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
    – Phil H
    18 hours ago










  • See revised answer, same as the book.
    – Phil H
    14 hours ago










  • @Phil H, thanks for confirming the books answer
    – tas75
    13 hours ago
















Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
– maxmilgram
22 hours ago




Could you add a picture or a more detailed description. I am especially stuck on this sentence "The bead moves in a horizontal circle about the line AB".
– maxmilgram
22 hours ago












@maxmilgram, I hope that helps
– tas75
22 hours ago




@maxmilgram, I hope that helps
– tas75
22 hours ago












I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
– Phil H
18 hours ago




I don't get your answer or the answer in the book. I'll post my free body diagram in the answer because it won't post in the comments.
– Phil H
18 hours ago












See revised answer, same as the book.
– Phil H
14 hours ago




See revised answer, same as the book.
– Phil H
14 hours ago












@Phil H, thanks for confirming the books answer
– tas75
13 hours ago




@Phil H, thanks for confirming the books answer
– tas75
13 hours ago










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Edit: I had the resultant of the strings at the wrong angle. Now corrected I get the same result as the book.



This should be a comment but a diagram won't post to the comments. Take a look and see if you agree.



enter image description here






share|cite|improve this answer























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    1 Answer
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    1 Answer
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    active

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    up vote
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    accepted










    Edit: I had the resultant of the strings at the wrong angle. Now corrected I get the same result as the book.



    This should be a comment but a diagram won't post to the comments. Take a look and see if you agree.



    enter image description here






    share|cite|improve this answer



























      up vote
      0
      down vote



      accepted










      Edit: I had the resultant of the strings at the wrong angle. Now corrected I get the same result as the book.



      This should be a comment but a diagram won't post to the comments. Take a look and see if you agree.



      enter image description here






      share|cite|improve this answer

























        up vote
        0
        down vote



        accepted







        up vote
        0
        down vote



        accepted






        Edit: I had the resultant of the strings at the wrong angle. Now corrected I get the same result as the book.



        This should be a comment but a diagram won't post to the comments. Take a look and see if you agree.



        enter image description here






        share|cite|improve this answer














        Edit: I had the resultant of the strings at the wrong angle. Now corrected I get the same result as the book.



        This should be a comment but a diagram won't post to the comments. Take a look and see if you agree.



        enter image description here







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited 14 hours ago

























        answered 18 hours ago









        Phil H

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