Question

Первые 5 км тело двигалось с постоянной скоростью 1.5 м/с,далее его скорость изменяется с 1.5 и становится 3 м/с и тело еще проходит 4 км,определите время,в течение которого двигалось тело-помогите решить задачу!

Answer 1

Ну, если переход с 1.5 на 3 перешёл мгновенно, то:
S1/V1+S2/V2=5000/1.5+4000/3. Дальше просто посчитать.

Answer 2

Problem Analysis

We are given that an object moves with a constant speed of 1.5 m/s for the first 5 km, and then its speed changes to 3 m/s. We need to determine the time it takes for the object to travel the entire distance.

Solution

To solve this problem, we can use the formula:

time = distance / speed

Let's break down the problem into two parts: the first 5 km and the remaining 4 km.

For the first 5 km: - Distance = 5 km = 5000 m - Speed = 1.5 m/s

Using the formula, we can calculate the time taken for the first 5 km:

time1 = 5000 m / 1.5 m/s

For the remaining 4 km: - Distance = 4 km = 4000 m - Speed = 3 m/s

Using the formula, we can calculate the time taken for the remaining 4 km:

time2 = 4000 m / 3 m/s

Finally, we can find the total time by adding the times for the first 5 km and the remaining 4 km:

total time = time1 + time2

Let's calculate the values.

Calculation

For the first 5 km: - Distance = 5000 m - Speed = 1.5 m/s

time1 = 5000 m / 1.5 m/s

For the remaining 4 km: - Distance = 4000 m - Speed = 3 m/s

time2 = 4000 m / 3 m/s

Finally, the total time is:

total time = time1 + time2

Answer

The time it takes for the object to travel the entire distance is the sum of time1 and time2.