Предмет: Математика, автор: Ggggfkdkd

Первые 120 км автомобиль ехал со скоростью
50 км/ч, следующие 190 км — со скоростью 60
км/ч, а затем 110 км — со скоростью 100 км/ч.
Найдите среднюю скорость автомобиля на
протяжении всего пути. Ответ дайте в км/ч

Ответы

Автор ответа: alapov
2

Ответ:

63 км/ч средняя скорость автомобиля

Пошаговое объяснение:

120 : 50 = 2  2/5 часа (время движения по первому участку)

190 : 60 = 3  1/6 часа (время движения по 2 участку)

110 : 100 = 1  1/10 часа (время движения по 3 участку)

2  2/5  + 3  1/6  + 1  1/10 = 20/3 часа  (время в пути)

120 + 190 +110 = 420 км - общее расстояние, которое проехал автомобиль

420 :  20/3 = 420 · 3/20  = 21 · 3 = 63 км/ч средняя скорость автомобиля

Похожие вопросы
Предмет: Русский язык, автор: ароин
Предмет: Английский язык, автор: Serega15445
Exercise1. Put in I must or I had to.
Пример: I had to go the bank yesterday to get some money.
1)It's late_____go now.
2) I dont't usually work on Saturdays but last Saturday______work.
3) I went to London by train last week. The train was fuul and____stand all the way.
4)______get up early tomorrow. I've got a lot to do.
5) I was nearly late for my appointment this morning____run to get there on time.
6) I forgot to phone David yesterday____phome him later today.

Exercise2. Complete the sentences. Use mustn't or needn't + one of these verbs:
forget, wait
1) I'm not ready yet but you____for me. You can go now and come later.
2) We_____to turn off the lights before we leave.

Exercise3. Complete the sentences. Use you should + one of these xverbs:
clean, go, take, visit, watch, wear
Пример: When you play tennis you should watch the ball.
1) It's late and you're very tired____to bad.
2) ____your teeth twice a day.
3)If you have time______the Science Museum. It's very interesting.
4) When you'rt driving_____a seat belt.
5) It's too far to walk from here to the statio._________a taxi.

Exercise4. Erite sentences with might.
Пример: (it's possible that I'll go to the cinema) I might go to cinema.
1) (it's possible that I'll see you tomorrow) I_______
2) (it's possible that Ann will forget to phone) _____________
3) (it's possible that it wd snow tody)________
4) (it's possible that I'll be late tonight)_________

Write sentences with might not.
5) (it's possible that Mary will not be here)_________
6) (it's possible that I won't have time to meet you) _________