Question

Камень брошен вертикально вверх со скоростью 20м/с. Определить путь, пройденный камнем за 3 с. Сопротивлением воздуха пренебречь.

Answer 1

Дано Vo=20 м/с   t=3 с   S- ?

S=h1+h2
очевидно время подъема t1=2 c

t1=Vo/g=20/10=2c
h1=Vo^2/2*g=20*20/20=20 м
t2=3-2=1c( время падения вниз)
h2=g*t2^2/2=10*1/2=5 м
S=20+5=25 м

Answer 2

Problem Analysis

We are given that a stone is thrown vertically upwards with an initial velocity of 20 m/s. We need to determine the distance traveled by the stone in 3 seconds, neglecting air resistance.

Solution

To solve this problem, we can use the equations of motion for uniformly accelerated motion. Since the stone is thrown vertically upwards, we can consider the acceleration due to gravity as -9.8 m/s^2.

Let's break down the problem step by step:

1. We know the initial velocity of the stone is 20 m/s. 2. The acceleration due to gravity is -9.8 m/s^2. 3. We need to find the distance traveled by the stone in 3 seconds.

Calculation

To find the distance traveled by the stone in 3 seconds, we can use the equation:

s = ut + (1/2)at^2

where: - s is the distance traveled - u is the initial velocity - t is the time - a is the acceleration

Substituting the given values into the equation, we have:

s = (20 m/s)(3 s) + (1/2)(-9.8 m/s^2)(3 s)^2

Simplifying the equation, we get:

s = 60 m - 44.1 m

Therefore, the distance traveled by the stone in 3 seconds is:

s = 15.9 m

Answer

The stone travels a distance of 15.9 meters in 3 seconds when thrown vertically upwards with an initial velocity of 20 m/s, neglecting air resistance.