осталось 20 минут .
Чтобы получить большую экономию в силе, Павел задумал объединить три механизма: наклонную плоскость, блоки и рычаг механизмы объединены в систему так, как это показано на рисунке, а для измерения силы Павел использует динамометр.

Какой величины потребуется сила F для перемещения груза, вес которого P=63Н, если высота наклонной плоскости h=0,6 м, длина наклонной плоскости l=1,8 м, плечи рычага l1=1,5 м и l2=3 м?

(ответ дай в виде целого числа).

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Ex.1

If they planned the robbery better, they would succeed.

If the police acted more quickly, they would prevent the robbery.

If he didn't drive so fast, he wouldn't have an accident.

The crime rate wouldn't increase if the last government's policy was more efficient.

The police wouldn't catch him if he didn't leave his fingerprints on the door.

Ex.2

If the police didn't act decisively, the criminal would escape.

if the police acted decisively, the criminal wouldn't escape.

If the police didn't apologize, Mr. Weskley wouldn't be satisfied.

If the robber forgot to take a map, he would get lost.

If the thief didn't run fast, the police would catch him.

If the court released the prisoner early, he would injure two police officers.

Ex.3 - не точно

1. If the man gave them a packet of sweets to eat during the journey, they would start fighting and one of the children would begin to choke on the sweets.

2. If the child couldn't breath and was in difficulties, the driver would turn round to help and would lose control of the car.

3. If it crashed into a group of people sitting at tables outside a cafe, five people would be injured, two seriously.

Объяснение:

1) When I come home, I will call you. 2) If I see him tomorrow, I will give him this book. 3) He will be glad if we tell him about it. 4) We are going to Paris next week, that's why we are buying tickets now. 5) I hope that they will be at home tomorrow. 6) When will he call? He will call as soon as he gets time. 7) Tomorrow my sister will go to the cinema if she buys tickets. 8) If you go shopping, buy me some coffee. 9) When she comes to school, she will listen teacher attentively. 10) He will agree if we invite them to the theatre. 11) I can't stand him talking like this. 12) Listen how well she is singing. She will stop singing if she hears you talking. 13) She often watches TV, but now she is not watching it, she is reading a book. 14) My brother is not at home now. Leave him a note. 15) Send me a letter if you go to Germany. 16) When I need help, I will ask them to help me. 17) He must finish his business before he leaves. 18) Do you still hope that they will call you? 19) She thinks that we will help her as soon as we can. 20) If you find my keys, return them to me.