What is the speed of a fly moving around a circle of 0.2 m with an acceleration of 2.1m/s^2? (Uniform Circular motion)

Charge is distributed along the entire x-axis with uniform density λ. how much work does the electric field of this charge distribution do on an electron that moves along the y-axis from y = a to y = b? (use the following as necessary: a, b, ε0, λ, and q for the charge on an electron.)