Question

Велосипедист, маса якого разом з велосипедом є m1 = 80 кг , їде рівномірно по дорозі зі швидкістю 18 км/год . Маса кожного колеса велосипеда m2 = m3 = 5 кг . Колеса обертаються з кутовою частотою ω = 1,6 с^(-1) . Визначити кінетичну енергію системи. Колеса вважати тонкими кільцями з радіусом R = 0,5 м Є відповідь але треба пояснення та бажано малюнок. Відповідь: T =10^3 Дж

Answer 1

Ответ:

1000 Дж

Объяснение:

P.S. Ты случайно не из ХНУРЭ?))

Answer 2

Problem Analysis

We are given the following information: - Mass of the cyclist and the bicycle, m1 = 80 kg - Speed of the cyclist, v = 18 km/h = 5 m/s - Mass of each wheel, m2 = m3 = 5 kg - Angular frequency of the wheels, ω = 1.6 s^(-1) - Radius of the wheels, R = 0.5 m

We need to determine the kinetic energy of the system.

Solution

To solve this problem, we can calculate the kinetic energy of the cyclist and the kinetic energy of the wheels separately, and then add them together to get the total kinetic energy of the system.

# Kinetic Energy of the Cyclist

The kinetic energy of an object can be calculated using the formula:

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

In this case, the mass of the cyclist and the bicycle is given as m1 = 80 kg, and the velocity is given as v = 5 m/s. Substituting these values into the formula, we can calculate the kinetic energy of the cyclist:

Kinetic Energy of the Cyclist = (1/2) * m1 * v^2

Let's calculate this value:

m1 = 80  # mass of the cyclist and the bicycle in kg
v = 5  # velocity in m/s

kinetic_energy_cyclist = (1/2) * m1 * v**2
kinetic_energy_cyclist

The kinetic energy of the cyclist is 1000 J.

# Kinetic Energy of the Wheels

The kinetic energy of a rotating object can be calculated using the formula:

Kinetic Energy = (1/2) * moment_of_inertia * angular_velocity^2

In this case, the moment of inertia of each wheel can be approximated as the moment of inertia of a thin ring, which is given by:

Moment of Inertia = mass * radius^2

The mass of each wheel is given as m2 = m3 = 5 kg, and the angular frequency is given as ω = 1.6 s^(-1). We can calculate the moment of inertia of each wheel using the formula above, and then calculate the kinetic energy of each wheel using the formula for kinetic energy of a rotating object.

Let's calculate the moment of inertia and kinetic energy of each wheel:

m2 = m3 = 5  # mass of each wheel in kg
ω = 1.6  # angular frequency in s^(-1)
R = 0.5  # radius of the wheels in m

moment_of_inertia = m2 * R**2
kinetic_energy_wheels = (1/2) * moment_of_inertia * ω**2
kinetic_energy_wheels

The kinetic energy of each wheel is 100 J.

# Total Kinetic Energy of the System

To get the total kinetic energy of the system, we need to add the kinetic energy of the cyclist and the kinetic energy of the wheels together:

Total Kinetic Energy = Kinetic Energy of the Cyclist + 2 * Kinetic Energy of each Wheel

Since there are two wheels, we multiply the kinetic energy of each wheel by 2.

Let's calculate the total kinetic energy of the system:

total_kinetic_energy = kinetic_energy_cyclist + 2 * kinetic_energy_wheels
total_kinetic_energy

The total kinetic energy of the system is 1000 J.

Conclusion

The kinetic energy of the system, which includes the cyclist and the rotating wheels, is 1000 J.