A glass sphere of volume 7litres contains air at 300K. It is connected to a pipe filled with mercury as shown in the figure. At the start, the mercury meniscus is level with the bottom of the sphere on both arms of the pipe. The air in the sphere is now heated and the mercury level on the right arm rises by 5mm. If the cross sectional area of the pipe is 10cm^2, what is the new temperature of the air ?