# 725 Centroid of windlift of airplane wing | Centroid of area

**Problem 725**

Repeat Problem 239 without using integration.

**Solution 725**

$R = \text{ area of parabola}$

$R = \frac{2}{3}bh = \frac{2}{3}(16)(360)$

$R = 3840 \, \text{ lb}$ *answer*

$\bar{x} = \text{ centroid of parabola}$

$x = \frac{3}{5}h = \frac{3}{5}(16)$

$x = 9.6 \, \text{ ft}$ *answer*