Pressure ( Normal, Fluids and Atmospheric )

• Pressure = Force divided by Area
• Pressure in Liquids = Height x Density x Gravitational Field Strength
• Gravitational Field Strength= N/kg
• In liquids, the pressure above the object is higher the the pressure deep down in the water
• As an object gets deeper into the liquid, pressure increases as there is more water above it
• Some objects float because collisions of eg water molecules exert a force to the object in the liquid. The bottom of the liquid is deeper than the top, so the object will feel an upwards force, which is upthrust.
• Upthrust occurs in liquids
• An object will float if it is not very dense
• An object will sink if it is very dense
• If the density of an object is greater than that of the fluid, then the object sinks to the bottom of the fluid
• If the density of an object is less than that of the fluid, then the object floats on the surface of the fluid