Как назвать движения, при которых ускорение постоянно? равно нулю?

Every country and every nation has its own customs and traditions. Englishmen are proud of their traditions and carefully keep them up. 
For example Englishmen are very fond of fireplaces, that's why many of them prefer the open fire to central heating.
They like to live in small houses with a small garden. People all over the world know the saying "The Englishman's home is his castle". 
They say that English people keep to their traditions even in meals. Porridge is the dish Englishmen are very fond of. Many of them eat porridge with milk and sugar for breakfast. As for the Scots, for example, they never put sugar in their porridge, they always put salt in it.
The English are tea-drinkers. They have it many times a day. Some Englishmen have tea for breakfast, tea at lunch time, tea after dinner, tea at tea-time and tea with supper. Some English families have "high tea" or big tea and no supper. For high tea they may have cold meat, bread and butter, cakes, and, of course, a lot of tea. The Englishmen always drink tea out of cups, never out of glasses.