Menurunkan rumus titik berat penampang setengah lingkaran
4. Penampang Setengah Lingkaran
a. Terhadap sumbu X
X^{2}+Y^{2}=R^{2}
Y^{2}=R^{2}-X^{2}
Y \times A=\int \bar{y} \times dA
Y \times \left ( \frac{1}{2}\pi R^{2} \right )=\int \frac{y}{2} \times y \times dx
Y=\frac{\int \frac{y}{2}.y.dx}{\frac{1}{2}\pi R^{2}}
Y=\frac{\int y^{2}.dx}{\pi R^{2}}
Y=\frac{2\int_{0}^{R}\left ( R^{2}-X^{2} \right ).dx}{\pi R^{2}}
Y=\frac{2\left [ R^{2}X-\frac{X^{3}}{3} \right ]_{0}^{R}}{\pi R^{2}}
Y=\frac{2\left [ R^{3}-\frac{R^{3}}{3} \right ]}{\pi R^{2}}
Y=\frac{2\left [ \frac{2}{3}R^{3} \right ]}{\pi R^{2}}
Y=\frac{4R}{3\pi }
b. Terhadap sumbu Y
X= 0
Ditulis oleh : Civil Engineering Library