Some forces require direct contact, while others, like gravity, act at a distance

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

Write the function getkthdigit(n, k) that takes a possibly-negative int n and a non-negative int k, and returns the kth digit of n, starting from 0, counting from the right

What is the rate of change in a objects position?