Предмет: Физика, автор: esfaw

Школьники бегали на время 4 км. Вася пробежал всю дистанцию со скоростью 10 км/ч,а Женя первую половину дистанции со скоростью 20 км/ч, а вторую шел со скоростью 5 км/ч. Кто из них финишировал первым? В ответе укажите его среднюю скорость в км/ч.

Ответы

Автор ответа: Persianka

tв=S/Vв=4/10=0,4 ч

tж=S/(2*Vж1)+S/(2*Vж2)=4/(2*20)+4/(2*5)=0,1+0,4=0,5 ч

Первым финишировал Вася. Его ср.скор. 10 км/ч

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Математика, автор: serhiypanchenko09

2 6/7 * (-1 6/15)=
Обчiслити!!!!!

5 лет назад

Предмет: Английский язык, автор: PO3ETO4KA

Помогите с английским
I. Use the correct tense-forms of the verbs in brackets.

1. I (bring) you a gift. You (like) it?

2. Why you (smell) the meat? It can't be bad. I (buy) it this morning.

3. It was Jane's birthday last Sunday. Knowing her taste I (make) up my mind to buy her a large box of chocolates.

4. The weather (get) better and better. I (feel) spring in the air.

5. Her plane (leave) at 6.40 tomorrow. I (promise) to take her to the airport.

6. Everybody realized of course that I (be) a foreigner.

7. It turned out that the windows (smash) with a hammer taken from the tool-shed.

II. Use the right article.

1. I'm always forgetting ... people's names.

2. ... only thing that matters is to find ... way home.

3. Mary said, «What... nice idea!»

4. North Wales seems ... good place for ... holiday.

5. She is anxious to find ... better job.

6. There's nothing like ... cheese for me for ... breakfast.

III. Choose the suitable preposition or postposition.

1. I arrived (to, at, -) home feeling very tired.

2. I didn't see you (on, in, at) the party on Sunday.

3. He studied French (at, on, in) Paris (since, for) a year.

4. I didn't feel very well when I woke (down, up).

5. You'll find the sport results (in, by, on) the back page of the newspaper.

IV Circle the suitable pronoun.

1) Yesterday we had supper with the neighbours of (our,

us, ours).

2) She left the house without saying (something, anything, nothing) to (somebody, nobody, anybody).3) (None, no, not) of the people I met there were English. 4 We've got (many, much, plenty) of time. 5. Not (every, all, many) the stories about this film are true.

V Put the words in the right order to make up a

sentence.

1 the/her/yet/has/cat/lady/found/old?

2 month/I/the/to/went/last/dentist/times/three/see.

3 lift/tomorrow/I'iya/to/give/the/you/station.

4 me/tooth/giving/again/this/is/trouble.

VI. Choose the right variant

1. My father was in hospital for six weeks.

a) For what?

b) How much?

c) For how long?

2. I'd like to help you.

a) You mustn't.

b) You would, wouldn't you?

c) You needn't, thank you.

5 лет назад

Предмет: Музыка, автор: ASavchenko132009

Ударный инструмент без определённой высоты звучания (10 букв)

5 лет назад

Предмет: Алгебра, автор: sabina45688

СРОЧНОО решите уранения 1)-x=0 2)x:4,2=3/2:6,3 3)2(x+1/5)-x=3 2/5 4)5-2(4+x)=-1 5)2,4x+6,3=7 1/2

8 лет назад

Предмет: Математика, автор: Ви8ктория

Юра старше Оли на 6 лет а Оля младше Юры в 4 раза
сколько лет оле а сколько юре?

8 лет назад