Question

СРОЧНО Мяч массой 200 г роняют с высоты 2 м без начальной скорости.Потери механической энергии в результате удара о пол составили 0,8 Дж.На какую высоту поднимется мяч после отскока от пола?Сопротивлением воздуха пренебречь.

Answer 1

200/2=100/0,8=125.
=) я рат помоч

Answer 2

......200/2=100/0,8=125

Answer 3

Calculation of the Height Reached by the Ball After Bounce

To calculate the height reached by the ball after bouncing off the floor, we can use the principle of conservation of mechanical energy. According to this principle, the total mechanical energy of a system remains constant if no external forces, such as air resistance, are acting on it.

In this case, the ball is dropped from a height of 2 meters without any initial velocity. The mechanical energy of the ball is initially in the form of gravitational potential energy. After the ball bounces off the floor, some of its mechanical energy is lost due to the impact with the floor. The remaining energy is converted back into gravitational potential energy as the ball reaches its maximum height after the bounce.

Let's denote the initial height of the ball as h, the mass of the ball as m, the acceleration due to gravity as g, and the loss of mechanical energy as E_loss.

The initial mechanical energy of the ball is given by the gravitational potential energy:

E_initial = m * g * h

After the bounce, the ball reaches its maximum height, denoted as h_max. At this point, all the remaining mechanical energy is in the form of gravitational potential energy:

E_final = m * g * h_max

The loss of mechanical energy during the bounce is given as E_loss = E_initial - E_final.

We are given that the loss of mechanical energy is 0.8 J, the mass of the ball is 200 g (0.2 kg), and the initial height is 2 m.

Let's substitute the given values into the equations and solve for h_max:

E_initial = m * g * h = 0.2 kg * 9.8 m/s^2 * 2 m = 3.92 J

E_final = E_initial - E_loss = 3.92 J - 0.8 J = 3.12 J

Now, we can solve for h_max:

m * g * h_max = E_final

0.2 kg * 9.8 m/s^2 * h_max = 3.12 J

h_max = 3.12 J / (0.2 kg * 9.8 m/s^2) = 1.59 m

Therefore, the ball will reach a height of approximately 1.59 meters after bouncing off the floor.

Please note that the calculation assumes no air resistance and neglects other factors that may affect the bounce of the ball.