Den Hartog’s Mechanics
A web-based solutions manual for statics and dynamics
The book
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Problems solved:
1–.
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Problem 43
As the roller is starting to go up over the plank, the contact force between the roller and the ground goes to zero. The free-body diagram for this condition is shown below.
To determine P, we take moments about A, the contact point between the plank and the roller.
\sum M_A = P \cdot 8 - 300 \cdot \sqrt{9^2 - 8^2} = 0
The solution is P = 155 lbs, which, except for roundoff, matches the answer in the back of the book.
Last modified: January 22, 2009 at 8:32 PM.