## University Calculus: Early Transcendentals (3rd Edition)

$$22,800,00 \space ft- lb$$
Work done, $W=\int_c^d F(x) dx$ We have : $F(x)= 8 \times 800 [\dfrac{(2) \times 4750-x}{(2) \times (4750)}]$ or, $$F(x)=6400 (1- \dfrac{x}{9500} ) lb$$ Now, $$W= (6400) \times \int_{0}^{4750} (1-\dfrac{x}{9500}) dx \\=6400 \times [4750-\dfrac{(4750)^2}{4 \times 4750 }] \\=22,800,00 \space ft- lb$$