Why did Caribbean migrants settle in Notting Hill?
Paddington station is very close to Notting Hill, and was the first London station at which the trains carrying Caribbean migrants stopped. Caribbean people gathered there to welcome the migrants and help them find accommodation. Many migrants already had friends or family in Notting Hill and wanted to live near them. The black community in Notting Hill grew larger.
Caribbean migrants had to pay high rents for poor, squalid housing. Landlords charged Caribbean people higher rents than white people for the same type of accommodation, leading to overcrowding. Landlords made few repairs to their houses as to spend money would reduce their profits.
It's curved because atmospheric pressure is affected by the density of the atmosphere, which also varies with height
The density of the atmosphere gets higher the closer you are to sea level, because the weight of the air above pushes down on the air below, compressing it
To make an object float, you need to make it less dense than the liquid you're trying to float it on, so it will have displaced a volume of water with a weight equal to its own weight before it's completely submerged