Problem 1-1|Stress | Mechanics of Materials| Ninth Edition| R.C. Hibbeler|

The shaft is supported by a smooth thrust bearing at B and a journal bearing at C. Determine the resultant internal loadings acting on the cross section at E.

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Problem 1-1 Figure

SOLUTION:

The free-body diagram is shown below.

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Solve for Cy by taking moment at point B

\sum M_B=0

C_y\left(8\right)+400\left(4\right)-800\left(12\right)=0

Pass a cutting plane at section E. The free-body diagram of the resulting figure is shown

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Take the sum of forces in the x-direction, and equate to zero

\sum F_x=0

N_E=0

Take the sum of forces in the y-direction and equate to zero

\sum F_y=0

V_E+1000-800=0

V_E=-200\:lb

Take the sum of moments at point E

\sum M_E=0

1000\left(4\right)-800\left(8\right)-M_E=0

M_E=-2400\:lb\cdot ft

The negative signs indicates that  V_E\:and\:M_E act in the opposite sense to that shown on the free-body diagram.

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