Question

Покоящееся тело начинает движение с постоянным ускорением в третью секунду оно проходит путь 5 м. Какой путь тело пройдет за 3 секунду.P.S.: ответ я знаю, мне, желательно, по подробней объяснить решение)

Answer 1

S=a*t*t/2; S=s1+s2+s3 (s1 - путь, пройденный за 1ю сек, s2 - за вторую...);
s1=a*t*t/2 при t=1, т.е. s1=a/2;
s2=(a*t*t/2 при t=2) - s1 = 4*a/2-a/2;
s3=(a*t*t/2 при t=3)- s1 -s2 = 9*a/2-a/2-4*a/2+a/2=5*a/2 = 5 по условию => a=2м/с;
S=2*3*3/2 = 9м
или
S = a*t^2/2

S = 2 * 3^2/2 = 9 м
3-я секунда - 5 метров - итого за 3 секунды 1+3+5 = 9 метров

Answer 2

Problem Statement

A body at rest starts moving with a constant acceleration. In the third second, it covers a distance of 5 meters. The question is, what distance will the body cover in 3 seconds?

Solution

To solve this problem, we need to use the equations of motion. The equation that relates distance, initial velocity, time, and acceleration is:

Distance = Initial Velocity * Time + (1/2) * Acceleration * Time^2

In this case, the body starts from rest, so the initial velocity is 0. The acceleration is constant, and we are given that the body covers a distance of 5 meters in the third second. We need to find the distance covered in 3 seconds.

Let's substitute the given values into the equation:

Distance = 0 * 3 + (1/2) * Acceleration * 3^2

Simplifying the equation:

Distance = (1/2) * Acceleration * 9

Now, we need to find the value of acceleration. We know that the body starts from rest and has a constant acceleration. Let's assume the acceleration is denoted by 'a'. In the third second, the body covers a distance of 5 meters. Using the equation of motion again, we can write:

5 = 0 * 3 + (1/2) * a * 3^2

Simplifying the equation:

5 = (1/2) * a * 9

Multiplying both sides by 2/9:

10/9 = a

Now, we have the value of acceleration. Let's substitute it back into the original equation:

Distance = (1/2) * (10/9) * 9

Simplifying the equation:

Distance = 10 meters

Therefore, the body will cover a distance of 10 meters in 3 seconds.

Answer

The body will cover a distance of 10 meters in 3 seconds.