Question

Автомобиль массой 2т поднимается в гору с уклоном 0,2. На участке пути 32м скорость автомобиля возросла от 21,6км/ч до 36км/ч. Считая движение автомобиля равноускоренным, определить силу тяги двигателя. Коэффициент трения равен 0,02.Решить через второй закон ньютона нужно.

Answer 1

Задачу можно решать с использованием закона сохранения энергии: A=0,5*(m*v^2-m*v0^2)+m*g*h+Ft*S; h=S*sin(a); Ft=k*m*g*cos(a); A=F*S;F*S=0,5*(m*v^2-m*v0^2)+m*g*S*sin(a)+k*m*g*cos(a)*S; m=2000; v=6; v2=10; g=9,8;sin(a)=0,2; cos(a)=1(примерно);k=0,02.Считайте!

Answer 2

Problem Analysis

We are given the following information: - The mass of the car is 2 tons. - The car is moving uphill with an incline of 0.2. - The car's speed increases from 21.6 km/h to 36 km/h over a distance of 32 m. - The coefficient of friction is 0.02.

We need to determine the force of the engine's traction using Newton's second law.

Solution

To solve this problem, we can use Newton's second law, which states that the net force acting on an object is equal to the product of its mass and acceleration. In this case, the net force is the sum of the force of traction and the force of friction.

Let's break down the solution into steps:

Step 1: Convert the mass of the car from tons to kilograms. Since 1 ton is equal to 1000 kg, the mass of the car is 2000 kg.

Step 2: Convert the speeds from km/h to m/s. The initial speed is 21.6 km/h, which is equal to 6 m/s, and the final speed is 36 km/h, which is equal to 10 m/s.

Step 3: Calculate the change in velocity. The change in velocity is the difference between the final velocity and the initial velocity. In this case, it is 10 m/s - 6 m/s = 4 m/s.

Step 4: Calculate the acceleration. The acceleration can be calculated using the formula: acceleration = change in velocity / time. In this case, the time is the distance divided by the average speed. The distance is given as 32 m, and the average speed is (6 m/s + 10 m/s) / 2 = 8 m/s. Therefore, the acceleration is 4 m/s / (32 m / 8 m/s) = 1 m/s^2.

Step 5: Calculate the force of friction. The force of friction can be calculated using the formula: force of friction = coefficient of friction * normal force. The normal force is equal to the weight of the car, which can be calculated using the formula: weight = mass * gravity. The acceleration due to gravity is approximately 9.8 m/s^2. Therefore, the weight of the car is 2000 kg * 9.8 m/s^2 = 19600 N. The force of friction is 0.02 * 19600 N = 392 N.

Step 6: Calculate the force of traction. The force of traction is equal to the net force acting on the car. The net force can be calculated using the formula: net force = mass * acceleration. Therefore, the force of traction is 2000 kg * 1 m/s^2 = 2000 N.

Answer

The force of traction exerted by the engine is 2000 N.

Explanation

When a car moves uphill, it experiences a force of gravity pulling it downwards and a force of friction opposing its motion. The force of traction exerted by the engine must overcome these forces to accelerate the car uphill. In this case, the force of traction is equal to the net force acting on the car, which is the product of its mass and acceleration. The force of friction can be calculated using the coefficient of friction and the weight of the car. By applying Newton's second law, we can determine the force of traction to be 2000 N.