Математический маятник длиной 1 м установлен в лифте.Найдите период колебаний маятника, если лифт движется вертикально вверх с ускорением 4 м/с2.

1437 см в квадрате сколько будет дм в квадрате и см в квадрате?

Помогите, пожалуйста! 

You have received a letter from your English-speaking pen friend Peter.

...Hope you had a great summer. What did you do?  Did you have a goog time? It is my birtgday next week and I can not wait!..

Write him a letter and answer his questions, then ask him about his birthday plans.

Начало такое:

Dear Peter,

Thanks for yor letter. It was nice of you to drop me a line.

Тема: "Неформальное письмо".