1. Torricelli’s BAROMETER used a glass tube filled with Hg suspended in a bowl of Hg. The pressure of the air molecules pushing on the bowl pushed the Hg up into the glass tube. The weight of the mercury in the tube was equal to the weight of the air pressing down on the mercury in the dish.

2. As atmospheric pressure increases… The mercury in the tube rises.

3. Ways to measure Standard Pressure(0˚C) 1 Standard Atmosphere is equal to:1 Standard Atmosphere is equal to: 760 mm Hg760 mm Hg 1013 millibars1013 millibars 101.3 kPa (kiloPascals) 1kPa=1000N/m 2101.3 kPa (kiloPascals) 1kPa=1000N/m 2 14.7 pounds/in 214.7 pounds/in 2 760 Torr760 Torr Dimensional analysis will be used to convert from one system to anotherDimensional analysis will be used to convert from one system to another

4. Buoyancy and Swimming Buoyancy is why most people float. Your body displaces water. When the mass of the water you displace is more than your mass, you float.Buoyancy is why most people float. Your body displaces water. When the mass of the water you displace is more than your mass, you float. Because of buoyancy you weigh very little in water.Because of buoyancy you weigh very little in water.

5. Buoyancy Buoyant Force – Force that acts against gravity causing objects to seem lighter.Buoyant Force – Force that acts against gravity causing objects to seem lighter. Fluid trying to enter the space of an object pushes up on object.Fluid trying to enter the space of an object pushes up on object. Based on the difference between density of the fluid and the objectBased on the difference between density of the fluid and the object

6. Buoyancy Ballast tanks can be filled with water or air to change the density of the boat.Ballast tanks can be filled with water or air to change the density of the boat.

7. Submarine action Positive buoyancy – density less than water – floats on top or is risingPositive buoyancy – density less than water – floats on top or is rising Neutral buoyancy – density is equal to water – remains at constant depthNeutral buoyancy – density is equal to water – remains at constant depth Negative buoyancy - sinksNegative buoyancy - sinks