Chapter 17, Problem 43P

* A 0.40-kg cart with charge $\text{+4}{\text{.0×10}}^{\text{-8}}\text{C}$ starts at rest on a horizontal frictionless surface 0.50 m from a fixed object with charge $\text{+2}{\text{.0×10}}^{\text{-8}}\text{C}$. When the cart is released, it moves away from the fixed object. (a) How fast is the cart moving when very far (infinity) from the fixed charge? (b) When 2.0 m from the fixed object?