Halliday-Cap 22-VOL.3- rar - p22 047, Exercícios de Engenharia Elétrica

Baixe Halliday-Cap 22-VOL.3- rar - p22 047 e outras Exercícios em PDF para Engenharia Elétrica, somente na Docsity! 47. The charge dq within a thin section of the rod (of thickness dx) is ρ A dx where A = 4.00× 10−4 m2 and ρ is the charge per unit volume. The number of (excess) electrons in the rod (of length L = 2.00 m) is N = q/(−e) where e is given in Eq. 22-14. (a) In the case where ρ = −4.00 × 10−6 C/m3, we have N = q −e = ρ A −e ∫ L 0 dx = |ρ| A L e which yields N = 2.00 × 1010. (b) With ρ = bx2 (b = −2.00 × 10−6 C/m5) we obtain N = b A −e ∫ L 0 x2 dx = |b| A L3 3 e = 1.33 × 1010 .