Final answer:
The linear charge density along the circular arc, calculated by dividing the total charge by the length of the arc, is approximately -107e/cm. The negative sign indicates the charge distribution's direction along the arc.
Step-by-step explanation:
The linear charge density along the circular arc can be calculated by dividing the total charge by the length of the arc. In this case, the total charge is -300e and the angle subtended by the arc is 40.0°. To find the length of the arc, we can use the formula: length = r * θ. where r is the radius of the arc and θ is the angle in radians. In this case, the radius is 4.00 cm and the angle is 40.0°, which is approximately 0.698 radians. Plugging in these values, we get length = (4.00 cm) * (0.698), length ≈ 2.79 cm. Now, we can calculate the linear charge density: linear charge density = total charge / length, linear charge density = -300e / (2.79 cm), linear charge density ≈ -107 e/cm