Question

Тіло масою 2 кг кидають вертикально вгору зі швидкістю 115 км/год. Чому дорівнює кінетична енергія тіла в момент кидка?(Відповідь в Дж, округляємо до цілого)

Answer 1

Ответ: ≈1020 Дж

Объяснение:

Eкин=mv²/2

m=2 kg

v=115 km/h = 115000 m/h = 115000/3600= m/s

v=1150/36= 31,9(4) m/s

Eкин=mv²/2=2*(31.9(4))²/2≈1020 Дж

Answer 2

Calculation of Kinetic Energy

To calculate the kinetic energy of an object, we can use the formula:

Kinetic Energy = (1/2) * mass * velocity^2

Given that the mass of the object is 2 kg and the velocity is 115 km/h, we need to convert the velocity from km/h to m/s before plugging it into the formula.

Conversion of Velocity from km/h to m/s

To convert the velocity from km/h to m/s, we can use the conversion factor:

1 km/h = 0.27778 m/s

So, the velocity of 115 km/h can be converted to m/s as follows:

115 km/h * (0.27778 m/s / 1 km/h) = 31.9444 m/s

Now that we have the mass and velocity in the correct units, we can calculate the kinetic energy.

Calculation of Kinetic Energy (continued)

Using the formula for kinetic energy and plugging in the values:

Kinetic Energy = (1/2) * 2 kg * (31.9444 m/s)^2

Simplifying the equation:

Kinetic Energy = (1/2) * 2 kg * 1021.6784 m^2/s^2

Kinetic Energy = 1021.6784 J

Therefore, the kinetic energy of the object at the moment of the throw is approximately 1022 J (rounded to the nearest whole number).