Вертолет масгой 1 т находится на высоте 50 м. на какой высоте его потенциальная энергия возрастет на 245 кДж?

2. Карандаш массой 30ги длиной 20 см лежит на поверхности стола. На сколько изменится потенциальная энергия карандаша, если его поставить вертикально?

3. На какую высоту следует поднять тело массой 2 кг, чтобы eго потенциальная энергия возросла на 19.6 Дж?

4. Какой станет потенциальная энергия пружины, если ее из недеформированного состояния сжать на 5 см? Коэффициент жесткости пружины равен 40н м.

5. При растяжении недеформированноїй пружины на 10 см ее потенинальная энергия стала 0,4 Дж. Найдите коэффициент жесткости пружины.​

The United Kingdom of Great Britain and Northern Ireland is situated on the British Isles. It consists of 4 parts: England, Scotland, Wales and Northern Ireland. England, Wales and Scotland occupy the territory of Great Britain. Northern Ireland is situated in the northern part of Ireland. The population is over 57 million people. The northern and western parts of the country are mountainous and are called the Highlands. All the rest: south, east and center are a vast plain, called the Lowlands. The mountains are not very high. The rivers are not very long. The most important of them are the Severn and the Thames. There are many beautiful lakes in Great Britain. Great Britain is a country with old cultural traditions and customs. The most famous educational centers are Oxford and Cambridge Universities. The United Kingdom is a monarchy and the Queen is the head of the state. But in practice it is ruled by the government with a Parliament at the head. нашел в книжке

There are four seasons in a year: winter, spring, summer and autumn. All seasons are good in their own way. Winter, for example, is full of celebrations, presents and snow. Spring is the time of nature awakening and flower blooming. Autumn can be rainy and yet beautiful, full of multi-coloured leaves. However, my favourite season is summer. I choose summer not only because my birthday is in June, but also because it’s the time of holidays. Summer is the season when the sun shines brightly, the sky is rarely cloudy and the water in the sea becomes warm enough to swim. Even if it becomes too hot, you can always go for a walk in the shady woods. I also like summer because there are many berries, fruit and vegetables, not to mention numerous flowers on the fields. Among them roses, dandelions, daisies, and other flowers. Sometimes the air in summer becomes stuffy, but occasional thunderstorms bring relief. After the thunderstorms the air becomes remarkably fresh and very often we can see the rainbow in the sky. Summer is also the time when I and my family go on holiday to the seaside. It’s a wonderful time, when we can have a rest from the intense academic year and relax. I think all children love summer because of long school holidays and I’m no exception. I also enjoy my free time, playing with my friends, watching TV, and doing other fun activities. Nevertheless, I don’t forget to do some useful reading from time to time.