1. A simple device that is used to test the strength of antifreeze in cars consists of a small tube that has several small, coloured spheres inside it. When antifreeze is admitted into the tube, some of the spheres will float, giving an indication of the strength of the antifreeze. How does this device work? 2. A laboratory thermometer reads 0.4C at the ice point and 100.9C at the steam-point. What temperature will the thermometer read when the true temperature is 18.2C? 3. A balloon is to be filled with helium (density 0.178 kg/m) while the air outside has density 1.29 kg/m. The mass of the empty balloon is 80.0 kg and it is to lift a load of 240 kg. What minimum volume is necessary for the lift off? Assume that the balloon material and the load occupy negligible volumes.