A copper collar is to fit tightly about a steel shaft whose diameter is 6.0000 cm at

Question:

A copper collar is to fit tightly about a steel shaft whose diameter is 6.0000 cm at 20°C. The inside diameter of the copper collar at that temperature is 5.9800 cm. To what temperature must the copper collar be raised so that it will just slip on the steel shaft, assuming that the steel shaft remains at 20°C?