What is linear charge density of the insulating shell

Question1

calculates the average velocity in following two cases.

(a) You walk 73.2m at the speed of 1.22m/s and then run 73.2m at the speed of 3.05m/s along a straight track.

(b) You walk for 1.00min at a speed of 1.22m/s and then run for 1.00min at 3.05m/s next to a straight track.

(c) Graph x versus t for both cases and indicate how the average velocity is found on graph.

Question2

An infinite line of charge with linear density λ1 = 7.7 μC/m is positioned along the axis of a thick insulating shell of inner radius a = 2.5 cm and outer radius b = 4.4 cm. The insulating shell is uniformly charged with the volume density of ρ = -696.0 μC/m3.

1. What is λ2, linear charge density of the insulating shell?

2. What is Ex (P), value of x-component of the electric field at point P, positioned a distance 6.8 cm along y-axis from line of charge?