3.33 • Uma canoa tem velocidade de \( 0,40 \mathrm{~m} / \mathrm{s} \) a sudeste em relação à Terra. A canoa se desloca em um rio que escoa a \( 0,50 \mathrm{~m} / \mathrm{s} \) para leste em relação à Terra. Determine o módulo, a direção e o sentido da velocidade da canoa em relação ao rio.

must be the charge of a Figure \( 23-40 \) shows a section of a \( R=3.00 \mathrm{~cm} \), with a charge per unit length of \( \lambda=2.00 \times 10^{-8} \mathrm{C} / \mathrm{m} \). What is the magnitude \( E \) of the electric field at radial distance (a) \( r=R / 2.00 \) and (b) \( r=2.00 R \) ? (c) Graph \( E \) versus \( r \) forthe range \( r=0 \) to 2.00R.

A \( 20-\mathrm{m} \) long steel wire (cross-section \( 1 \mathrm{~cm}^{2} \), Young's modulus \( 2 \times 10^{11} \mathrm{~N} / \mathrm{m}^{2} \) ), is subjected to a load of \( 25,000 \mathrm{~N} \). How much will the wire stretch under the load? \( \begin{array}{lllll}\text { A) } 0.25 & \text { B) } & 2.5 \mathrm{~cm} & \text { C) } 12.5 \mathrm{~cm} & \text { D) } 25 \mathrm{~cm}\end{array} \) \( \begin{array}{llll} & \text { B) } 1.25 \mathrm{~cm}\end{array} \)

A \( 20-\mathrm{m} \) long steel wire (cross-section \( 1 \mathrm{~cm}^{2} \), Young's modulus \( 2 \times 10^{11} \mathrm{~N} / \mathrm{m}^{2} \) ), is subjecte to a load of \( 25,000 \mathrm{~N} \). How much will the wire stretch under the load? \( \begin{array}{lllll}\text { A) } 0.25 & \text { B) } 2.5 \mathrm{~cm} & \text { C) } 12.5 \mathrm{~cm} & \text { D) } 25 \mathrm{~cm} & \text { E) } 1.25\end{array} \)

(c) Vektor kedudukan sebuah dron \( A, I \) saat selepas meninggalkan tempat berlepas ialah \( t\left(\frac{30}{15}\right) \) manakala vektor kedudukan dron \( B \) ialah \( \left(\frac{50}{5}\right)+t\left(\frac{10}{10}\right) \). Tentukan halaju bagi dron \( A \) dan dron B. Adakah dron \( A \) dan dron \( B \) akan bertembung? The position vector of a drone \( A, t \) seconds afler leaving the takeoff point is \( t\left(\frac{30}{15}\right) \) while the position vector of drone B is \( \left(\frac{50}{5}\right)+t\left(\frac{10}{10}\right) \). Determine the velocity of drone \( A \) and drone B. Will drone \( A \) and drone B collide? [3 markah/marks]

A lamp hangs vertically from a cord in a descending elevator that accelerates at \( 2.4 \mathrm{~m} / \mathrm{s}^{2} \). If the tension in the cord is 89 N . The mass of the lamp in \( (\mathrm{kg}) \) is: