Mirenda

A closed box is filled with dry ice at a temperature of -78.5 degree C, while the outside temperature is 21.0 degree C. The box is cubical, measuring 0.350m on a side, and the thickness of the walls is 3.00*10^-2 m. In one day, 3.10*10^6 J of heat is cond...

The A string on a string bass is turned to vibrate at a fundamental frequency of 55.0Hz. If the tension in the string were increased by a factor of four, what would be the new fundamental frequency? I need some guides to do it. Thx.