Floating and sinking

• Anything that floats has an upwards force on it. This occurs in water or a liquid most often but can in air (e.g. helium balloon)
• The water exerts a bigger force upwards than the air does downwards when an object floats.
• (Pressure at the bottom x area at the bottom) - (pressure at the top x area at the top)= weight
• Some objects sink and others float. This is to do with the density and weight of the object.
• Th upward force upon an object is equal to the water that it displaces
• Weight(N) = mass(kg) x gravitational field strength (10N/kg on Earth)