This article contains online calculators which can calculate discharge times for specified discharge current using battery capacity, the capacity rating (i.e. 20 hour rating, 100 hour rating etc) and Peukert's exponent.
This online calculator calculates unknown (whether force, charge or distance) using known values using Coulomb's law scalar formula. It can be used to solve physics problems.
These online calculators computes various parameters for charging and discharging the capacitor with the resistor