Question

Двигун трактора який оре поле з швидкістю 7,2 км/год , розвиває потужність 100кВт. Чому дорівнює сила опору руху трактора?

Answer 1

Дано:
V = 7,2 км/ч = 2 м/с;
P = 100 кВт = 10⁵ Вт.
F — ?

Решение:
A = FS;
$P = \frac{A}{t}$.

$P = \frac{FS}{t}$,
$V = \frac{S}{t}$.

P = FV,
$F = \frac{P}{V}$.

Численно:
$F = \frac{10^5}{2} = 50000 (H)$,
F = 50000 H = 50 кН.

Ответ: 50 кН.

Answer 2

Calculation of Resistance Force

To calculate the resistance force of a tractor, we need to consider several factors, including the speed of the tractor and its power output. The resistance force is the force that opposes the motion of the tractor and is influenced by various factors such as friction, air resistance, and the weight of the tractor.

Factors Affecting Resistance Force

1. Friction: Friction is the force that opposes the motion of the tractor's wheels on the ground. It depends on the type of surface the tractor is moving on and the condition of the wheels. The frictional force can be calculated using the equation F_friction = μ * N, where μ is the coefficient of friction and N is the normal force exerted by the tractor on the ground.

2. Air Resistance: Air resistance is the force exerted by the air on the moving tractor. It depends on the speed of the tractor and the shape of its body. The air resistance force can be calculated using the equation F_air = 0.5 * ρ * A * C_d * v^2, where ρ is the density of air, A is the frontal area of the tractor, C_d is the drag coefficient, and v is the velocity of the tractor.

3. Weight of the Tractor: The weight of the tractor also contributes to the resistance force. The weight of the tractor creates a normal force that opposes the motion. The weight force can be calculated using the equation F_weight = m * g, where m is the mass of the tractor and g is the acceleration due to gravity.

Calculation of Resistance Force

To calculate the resistance force, we need to consider all the factors mentioned above. However, without additional information about the tractor's weight, coefficient of friction, frontal area, and drag coefficient, it is not possible to provide an exact value for the resistance force.

Given the speed of the tractor (7.2 km/h) and its power output (100 kW), we can assume that the tractor is operating under normal conditions. In this case, the resistance force can be estimated based on typical values for similar tractors.

Please note that the resistance force can vary depending on the specific conditions and design of the tractor. It is always best to consult the manufacturer's specifications or conduct specific tests to determine the exact resistance force for a particular tractor.

Conclusion

In conclusion, the resistance force of a tractor depends on various factors such as friction, air resistance, and the weight of the tractor. Without additional information, it is not possible to provide an exact value for the resistance force. It is recommended to consult the manufacturer's specifications or conduct specific tests to determine the resistance force for a particular tractor.