определите изменение кинетической и потенциальной энергии парашютиста массой m=70кг , спускающегося с постоянной скоростью v=5.0 m/с в течение

колебаний до 10 см.

I think celebrating “Mother’s Day” once a year is a very good idea.
So we decided to have a special celebration of Mother’s Day. We thought it a fine idea. We knew how much Mother did for us and so we decided that we should do everything we could to make Mother happy.
We decided to decorate the house with flowers. We asked Mother to arrange the decoration because she always does it on holidays. My sisters got new hats for such an important day. We wanted to buy a new hat for Mother too, but she said that she liked her old hat better and didn’t want a new one.
Well, after breakfast we decided to take Mother for a beautiful drive away into the country. Mother is never able to go to the country because she is busy in the house nearly all the time.
But then we changed the plan a little.
Father decided to take Mother fishing.
When everything was ready for the trip we asked Mother to prepare some sandwiches.
Well, when the car came to the door, we saw that there was not enough room in it for us all. Father said that he could stay at home and work in the garden. Then the two girls, Anne and Mary, said that they could stay at home, but as they had new hats, it would be a pity if no one looked at them.
In the end it was decided that Mother could stay at home and make dinner. Mother doesn’t like fishing.
So we all drove away, and Mother stood and watched us from the verandah as long as she could see us.
Well, we had a very nice day in the country. Father caught a lot of big fish and the girls met some friends and they talked about hats. It was quite late when we got back.
At last everything was ready and we sat down to a wonderful dinner. Mother got up and down many times during dinner; she brought things from the kitchen and carried the dishes away.
When the dinner was over all of us wanted to help Mother to wash the dishes. But Mother said that she could do it herself, and so we let her because we wanted to make her happy.
It was quite late when it was all over, and we all kissed Mother before going to bed. She said it had been the most wonderful day in her life. Перевод с английского на русский

б)-2v в)-4v г)4v

15. Найти кинетическую и потенциальную энергии самолёта массой 1 т, летящего на высоте 5 км со скоростью 720 км/ч.