1. The problem statement, all variables and given/known data A 85.0 g hollow copper cylinder is 70.0 cm long and has an inner diameter of 1.0 cm. The current density along the length of the cylinder is 1.20×10^5 A/m^2. What is the current in the cylinder? 2. Relevant equations possibly J = I/A where J is the current density 3. The attempt at a solution I tried finding the current by using the formula I = JA, but when I did that, I didn't get the correct answer. Other than doing that, I have no idea about how to do this problem. Any pointers helping me to get started would be greatly appreciated.