Q1. A 0.390 long cylindrical capacitor consists of a solid conducting core with a radius of 1.30 and an outer hollow conducting tube with an inner radius of 2.15. The two conductors are separated by air and charged to a potential difference of 6.20.

Compute the charge per length for the capacitor.

Q2. A toy train is pushed forward and released at x_0 = 2m with a speed of 2m/s. It rolls at a steady speed for 2s, and then one wheel begins to stick. The train comes to a stop 6m from the point at which it was released. What is the magnitude of train's acceleration after its wheel begins to stick?