-
Кран поднимает груз массой 2т. Чему равна работа, совершаемая краном за первые 5сек, если скорость поднятия равна 30м\мин?
Ответы 1
-
За первые 5 секунд (1/12 мин) подняли груз на высоту 30*1/12м. Совершенная работа=20000Н*30/12м =50 кДж
-
Автор:
almudenawalker - 6 лет назад
-
0
-
-
Добавить свой ответ
Еще вопросы
-
ОПИШИТЕ.ЧТО ВЫ ВИДИТЕ ЗИМОЙ ИЗ ОКНА СВОЕГО ДОМА
-
Предмет:
Русский язык -
Автор:
dudley - 6 лет назад
-
Ответов:
1 -
Смотреть
-
-
Помогите найти времена Past и Present Perfect в этом тексте.
What finally awoke Ben was the engine coughing.
«Please wake up!» shouted Davy. «What’s the matter?»
«Push the lever forward,» whispered Ben.
Davy couldn’t have known about the lever and now Ben wasn’t able to point to it. But the boy saw the direction of his father’s eyes in time and the engine took up again.
«What direction do I take?» Davy cried again. «You’re not telling me how to get the right direction.»
«Follow the coast. Keep it on your right. And for God’s sake, don’t do anything else. It’ll be all right, Davy…» Ben could see the sharp profile of Davy’s pale face with his dark eyes. The boy had remembered how to level off and to keep the speed. «He’ll do it,» Ben whispered to himself and then fainted again.
At three thousand feet, on his own, Davy did not think he could ever cry again.
He had run out of tears. He had boasted only once in his ten years of life that his father was a pilot. He had remembered everything his father had told him about flying, but he had guessed a lot more that his father had not told him. Now Davy couldn’t even look at his father because he was horribly covered in blood. He didn’t want his father to die, but he knew that it was now a possibility. People did die.
The tears that Davy thought had dried up in him were now in his dark eyes, and he felt them running down his cheeks.
Ben felt a sharp pain and opened his eyes. «Davy! What’s happened? What are you doing!» he managed to shout.
«We are almost there. I can see the buildings of Cairo,» Davy said. «But the plane doesn’t want to go down.»
«Cut your engine. …»
«I did, but it doesn’t seem to make a difference.»
«Use the tail lever,» Ben said, and the plane put its nose down into a dive.
«Cut your engine!» Ben shouted again. He knew that getting a plane off the ground and flying it was easy but getting it down was another thing. The wind was blowing them back up. They lost air speed now because the nose was up. If the engine stopped at this height in this wind, they’d crash into a thousand pieces. …
They were approaching the airfield and the dust was like a yellow sea over the land. But then Ben saw the plane. «Look out! You’ll hit that plane,» Ben yelled.
Ben could see a big four-engined plane that was taking off. If it was only taking off and not testing its motors, they’d be all right. Ben closed his eyes and when he opened them again, the big plane was directly in their path but moving so quickly that they were going to miss it.
Now the yellow dust was just below them. «Six inches,» Ben cried to Davy painfully. «Six inches, Davy… Wait! Not yet! Not yet…!» he cried.
It was when they reached the last inch from the ground that Ben lost his nerve at last. He was trying to shout, «Now! Now! NOW!» but fainted again. He hardly felt it when the plane’s wheels hit the ground. When the plane’s tail finally touched down, Ben knew it was the last inch of it. The plane moved uncontrollably for a while and when at last it stopped dead, he heard only silence and thought that it wasn’t time to give in yet.-
Предмет:
Английский язык -
Автор:
danielle - 6 лет назад
-
Ответов:
1 -
Смотреть
-
-
сколько н в слове сказа...о
-
Предмет:
Русский язык -
Автор:
clarence96 - 6 лет назад
-
Ответов:
6 -
Смотреть
-
-
12 баллов!!!!!!!
Zn no3 2--->
электронный баланс
-
Предмет:
Химия -
Автор:
roryconrad - 6 лет назад
-
Ответов:
5 -
Смотреть
-
Топ пользователей
-
Fedoseewa27
35934 -
Devilian
2792 -
Pikachu
2228 -
hobbesbowers
2116 -
kaylynnbarron676
1818 -
女fei
1240 -
yulia-kaplina
1158 -
Poinntt
946 -
Bars
930 -
Queenmagic18
770
How much to ban the user?
1 hour
1 day
100 years