Question

Спортсмен,двигаясь равноускоренно из состояние покоя,пробежал 40 м своего пути за 28 сек.За какое время он преодолел первые 10 м своего пути?За какое время он преодолеет первую половину своей дистанции?

Answer 1

S=40

t=28

V=? сначало найдем скорость! V=S/t   V=40/28=1,4м/с

теперь узнаем время за первые 10 метров t= 10/1,4=7с

теперь найдем время за половину дистанции t= 20/1,4=14с 

Вот и все!)  

Answer 2

Problem Analysis

We are given that a sportsman, starting from rest, covers a distance of 40 meters in 28 seconds. We need to determine the time it takes for the sportsman to cover the first 10 meters of the distance and the time it takes to cover the first half of the distance.

Solution

To find the time it takes for the sportsman to cover the first 10 meters of the distance, we can use the concept of uniform acceleration. Since the sportsman is moving with constant acceleration, we can use the equation:

distance = initial velocity * time + (1/2) * acceleration * time^2

In this case, the initial velocity is 0 m/s (starting from rest), the distance is 10 meters, and the acceleration is the same throughout the motion. We need to find the time it takes to cover the first 10 meters, so we rearrange the equation to solve for time:

time = (2 * distance) / (acceleration)

To find the time it takes to cover the first half of the distance, we can use the same equation, but with a distance of 20 meters.

Let's calculate the values using the given information.

Calculation

For the first 10 meters: - Distance = 10 meters - Acceleration = ? - Time = ?

For the first half of the distance: - Distance = 20 meters - Acceleration = ? - Time = ?

Answer

To calculate the time it takes for the sportsman to cover the first 10 meters of the distance, we need to find the acceleration. Unfortunately, the given information does not provide the necessary data to calculate the acceleration. Therefore, we cannot determine the exact time it takes to cover the first 10 meters or the first half of the distance.

If you have any additional information or if there is anything else I can help you with, please let me know!