Answer:
1) A 1L bottle, with a height of 30cm, full of water is emptied. The bottle is filled with oil (density = 920 kg/m^3). Calculate the change in pressure of the bottom of the first bottle. If you decide to put potatoes (assume its density is 1,8 kg/m^3), each one of a volume V = 10 cm^3, will they float?
2) The fusion temperature of the Nitrogen is -210°C and its boiling temperature is 77K. Calculate the difference between the fusion temperature and the boiling temperature.