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VinnyCee
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Kinetics in Nromal and Tangential coordinates - SPINNING ROD W/ SPOOL
The 2-kg spool fits loosely on the inclined rod for which the coefficient of static friction is \mu_s\,=\,0.2. If the spool is located 0.25 m from A, determine the maximum speed the spool can have so that it does not slip up the rod.
http://img207.imageshack.us/img207/6962/problem13770pa.jpg
Here is what I have for this problem, but it is wrong according to the answer in the text:
sin\,\theta\,=\,\frac{3}{5}
\theta\,=\,36.9
\sum\,F_x\,=\,N\,cos\,53.1\,-\,f_s\,cos\,36.9\,=\,m\,a_n
\sum\,F_y\,=\,N\,sin\,53.1\,+\,f_s\,sin\,36.9\,-\,m\,g\,=\,m\,a_y
N\,=\,\frac{m\,g}{sin\,53.1\,+\,\mu_s\,sin\,36.9}
N\,=\,21.31\,N
Then I use another version of the F_x equation to solve for v_{max}:
N\,cos53.1\,-\,N\,\mu_s\,cos\,36.9\,=\,m\,\frac{v_{max}^2}{\rho}
v_{max}^2\,=\,\frac{9.39}{10}
v_{max}\,=\,0.969\,\frac{m}{s}
The answer is 1.48 in the text though! Any suggestions?
The 2-kg spool fits loosely on the inclined rod for which the coefficient of static friction is \mu_s\,=\,0.2. If the spool is located 0.25 m from A, determine the maximum speed the spool can have so that it does not slip up the rod.
http://img207.imageshack.us/img207/6962/problem13770pa.jpg
Here is what I have for this problem, but it is wrong according to the answer in the text:
sin\,\theta\,=\,\frac{3}{5}
\theta\,=\,36.9
\sum\,F_x\,=\,N\,cos\,53.1\,-\,f_s\,cos\,36.9\,=\,m\,a_n
\sum\,F_y\,=\,N\,sin\,53.1\,+\,f_s\,sin\,36.9\,-\,m\,g\,=\,m\,a_y
N\,=\,\frac{m\,g}{sin\,53.1\,+\,\mu_s\,sin\,36.9}
N\,=\,21.31\,N
Then I use another version of the F_x equation to solve for v_{max}:
N\,cos53.1\,-\,N\,\mu_s\,cos\,36.9\,=\,m\,\frac{v_{max}^2}{\rho}
v_{max}^2\,=\,\frac{9.39}{10}
v_{max}\,=\,0.969\,\frac{m}{s}
The answer is 1.48 in the text though! Any suggestions?
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