# 233 A force creating counterclockwise and clockwise moments

**Problem 233**

In Fig. P-231, a force P intersects the X axis at 4 ft to the right of O. If its moment about A is 170 ft·lb counterclockwise and its moment about B is 40 ft·lb clockwise, determine its y intercept.

**Solution 233**

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Resolve force P into components at its x-intercept

$M_B = 40$

$M_B = 40$

$2P_y = 40$

$P_y = 20 \, \text{ lb}$

$M_A = 170$

$3P_x + 4P_y = 170$

$3P_x + 4(20) = 170$

$P_x = 30 \, \text{ lb}$

Resolve force P into components at its y-intercept

$M_A = 170$

$(3 + b)P_x = 170$

$(3 + b)(30) = 170$

$b = \frac{8}{3}$

Thus, y intercept of force P is (0, -8/3). *answer*

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