Question

1. Железный куб с ребром 5см тянут по горизонтальной поверхности стола, прикладывая силу 15Н. Коэффициент трения куба о стол равен 0,4. Определите ускорение куба. Сроооочно!!!!

Answer 1

Все просто 15 * 0,4=6

Answer 2

Problem Analysis

We are given the following information: - The iron cube has a side length of 5 cm. - The force applied to the cube is 15 N. - The coefficient of friction between the cube and the table is 0.4.

We need to determine the acceleration of the cube.

Solution

To solve this problem, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration.

The net force acting on the cube is the difference between the applied force and the force of friction. The force of friction can be calculated using the equation:

Frictional force = coefficient of friction × normal force

The normal force is the force exerted by the table on the cube and is equal to the weight of the cube, which can be calculated using the equation:

Weight = mass × gravitational acceleration

Since the cube is on a horizontal surface, the normal force is equal to the weight of the cube.

Let's calculate the acceleration of the cube step by step.

1. Calculate the weight of the cube: - The side length of the cube is 5 cm, which is equal to 0.05 m. - The volume of the cube is given by Volume = (side length)^3. - The density of iron is approximately 7,860 kg/m^3. - The mass of the cube can be calculated using the equation Mass = Density × Volume. - Calculate the weight of the cube using the equation Weight = Mass × Gravitational acceleration.

2. Calculate the force of friction: - Use the equation Frictional force = Coefficient of friction × Normal force.

3. Calculate the net force: - The net force is the difference between the applied force and the force of friction.

4. Calculate the acceleration: - Use the equation Net force = Mass × Acceleration to solve for acceleration.

Let's perform the calculations.

Calculation

1. Calculate the weight of the cube: - Side length of the cube = 0.05 m. - Volume of the cube = (0.05 m)^3 = 0.000125 m^3. - Density of iron = 7,860 kg/m^3. - Mass of the cube = 7,860 kg/m^3 × 0.000125 m^3 = 0.9825 kg. - Gravitational acceleration = 9.8 m/s^2. - Weight of the cube = 0.9825 kg × 9.8 m/s^2 = 9.6255 N.

2. Calculate the force of friction: - Coefficient of friction = 0.4. - Normal force = Weight of the cube = 9.6255 N. - Frictional force = 0.4 × 9.6255 N = 3.8502 N.

3. Calculate the net force: - Applied force = 15 N. - Net force = Applied force - Frictional force = 15 N - 3.8502 N = 11.1498 N.

4. Calculate the acceleration: - Net force = Mass × Acceleration. - Acceleration = Net force / Mass = 11.1498 N / 0.9825 kg = 11.35 m/s^2.

Answer

The acceleration of the iron cube is 11.35 m/s^2.

Please note that the above calculations are based on the given information and assumptions.