Question

Физик хочет выяснить, с какой скоростью он может бросить мяч. Он бросает мяч горизонтально на высоте своего плеча, 1,2 м от поверхности земли. Мяч падает на землю в 6 м от того места, где стоит физик. Чему равна начальная скорость мяча?

Answer 1

По горизонтали мяч летит с постоянной начальной скоростью Vo. Поэтому горизонтальная координата будет равна

х = Vo·t,

х = 6м тогда время до приземления равно

t = 6/Vo.                 (1)

По вертикали мяч летит с ускорением g = 10м/с², направленным вертикально вниз.

Вертикальная координата

у = -0,5gt² + Уо

Поскольку Уо = 1,2м, а при t = 6/Vo  у = 0, то

0 = -0,5·10· 36/Vo² + 1,2

1,2 = 180/Vo²

Vo²= 180:1,2

Vo² = 150

Vo = √150 ≈ 12,2(м/с)

Ответ: начальная скорость Vo = √150 ≈ 12,2м/с

 

 

 

Answer 2

решаем задачу по формуле L=V*(корень квадратный из 2H/g); L=6; H=1,2; g=9,8. V=6/(квадратный корень 2H/g), V=12,12 м/с

Answer 3

Calculation of Initial Velocity of the Ball

To determine the initial velocity of the ball, we can use the equations of motion for projectile motion. In this case, the ball is thrown horizontally, which means its initial vertical velocity is zero. The only force acting on the ball is gravity, which causes it to accelerate downward.

We can use the following equations to solve for the initial velocity of the ball:

1. The horizontal distance traveled by the ball can be calculated using the equation:

d = v₀ * t

where: - d is the horizontal distance traveled by the ball (6 m in this case) - v₀ is the initial velocity of the ball (what we want to find) - t is the time of flight of the ball

2. The time of flight of the ball can be calculated using the equation:

t = √(2h / g)

where: - h is the vertical distance between the release point and the landing point of the ball (1.2 m in this case) - g is the acceleration due to gravity (approximately 9.8 m/s²)

By substituting the value of t into the equation for d, we can solve for v₀.

Let's calculate the initial velocity of the ball using these equations.

Calculation:

Using the equation t = √(2h / g), we can calculate the time of flight of the ball:

t = √(2 * 1.2 / 9.8) ≈ 0.49 s

Now, we can substitute the value of t into the equation d = v₀ * t to solve for v₀:

6 = v₀ * 0.49

Solving for v₀, we get:

v₀ = 6 / 0.49 ≈ 12.24 m/s

Therefore, the initial velocity of the ball is approximately 12.24 m/s.

Please note that the calculations provided are based on the given information and assumptions about the absence of air resistance and other factors that may affect the motion of the ball.