Question

От пристани в одно и то же время в противоположных направлениях отошли 2 теплохода. Один пошёл со скоростью 40 км/ ч, а другой со скоростью на 10 км/ч меньшей. Какое расстояние будет между ними через 4 часа после начала движения?

Answer 1

1)40-10=30км/ч
2)40×4=160км
3)30×4=120км
4)160-120=40км
Ответ: 40 км.

Answer 2

Problem Analysis

We have two boats that start from the same dock at the same time but in opposite directions. One boat travels at a speed of 40 km/h, while the other boat travels at a speed 10 km/h slower. We need to find the distance between the two boats after 4 hours.

Solution

To find the distance between the two boats after 4 hours, we need to calculate the distance each boat has traveled.

Let's start by calculating the distance traveled by the first boat, which is traveling at a speed of 40 km/h. The formula to calculate distance is:

Distance = Speed × Time

For the first boat, the distance traveled after 4 hours is:

Distance1 = 40 km/h × 4 hours

Now, let's calculate the distance traveled by the second boat, which is traveling at a speed 10 km/h slower. The speed of the second boat is 40 km/h - 10 km/h = 30 km/h. Using the same formula, the distance traveled by the second boat after 4 hours is:

Distance2 = 30 km/h × 4 hours

Finally, to find the distance between the two boats, we subtract the distance traveled by the second boat from the distance traveled by the first boat:

Distance between the two boats = Distance1 - Distance2

Let's calculate the distances and find the answer.

Calculation

Distance1 = 40 km/h × 4 hours = 160 km

Distance2 = 30 km/h × 4 hours = 120 km

Distance between the two boats = 160 km - 120 km = 40 km

Answer

The distance between the two boats after 4 hours of travel is 40 km.