Question

Помогите пожалуйста решить задачу. К телу массой 5кг покоящемуся на горизонтальной поверхности прикладывается в горизонтальном направлении сила равная по модулю 4Н. определить работу этой силы за 3с действия если коэффициент трения скольжения равен 0,1

Answer 1

Ответ:

4формулы.надеюсь ,что и как именно находить,знаешь.

Объяснение:

Answer 2

Problem Analysis

We are given the following information: - Mass of the body, m = 5 kg - Applied force, F = 4 N - Time, t = 3 s - Coefficient of sliding friction, μ = 0.1

We need to find the work done by the applied force over a time period of 3 seconds.

Solution

The work done by a force is given by the formula:

Work = Force × Distance

In this case, the force is applied horizontally, so the distance is the displacement of the body in the horizontal direction.

To find the displacement, we need to consider the forces acting on the body. There are two forces to consider: the applied force and the force of friction.

The force of friction can be calculated using the formula:

Frictional Force = Coefficient of Friction × Normal Force

The normal force is the force exerted by the surface on the body and is equal to the weight of the body, which can be calculated using the formula:

Weight = Mass × Acceleration due to Gravity

The acceleration due to gravity is approximately 9.8 m/s^2.

Once we have the frictional force, we can calculate the net force acting on the body using the formula:

Net Force = Applied Force - Frictional Force

The net force will determine the acceleration of the body using Newton's second law:

Net Force = Mass × Acceleration

Finally, we can calculate the displacement using the formula:

Displacement = Initial Velocity × Time + (1/2) × Acceleration × Time^2

Since the body is initially at rest, the initial velocity is zero.

Let's calculate the work done step by step.

Calculation

1. Calculate the weight of the body: - Weight = Mass × Acceleration due to Gravity - Weight = 5 kg × 9.8 m/s^2

2. Calculate the frictional force: - Frictional Force = Coefficient of Friction × Normal Force - Frictional Force = 0.1 × Weight

3. Calculate the net force: - Net Force = Applied Force - Frictional Force

4. Calculate the acceleration: - Net Force = Mass × Acceleration - Acceleration = Net Force / Mass

5. Calculate the displacement: - Displacement = Initial Velocity × Time + (1/2) × Acceleration × Time^2 - Since the body is initially at rest, the initial velocity is zero.

6. Calculate the work done: - Work = Force × Distance

Let's calculate the values step by step.

Calculation

1. Calculate the weight of the body: - Weight = Mass × Acceleration due to Gravity - Weight = 5 kg × 9.8 m/s^2

The weight of the body is 49 N.

2. Calculate the frictional force: - Frictional Force = Coefficient of Friction × Normal Force - Frictional Force = 0.1 × Weight

The frictional force is 4.9 N.

3. Calculate the net force: - Net Force = Applied Force - Frictional Force

The net force is 4 N - 4.9 N.

4. Calculate the acceleration: - Net Force = Mass × Acceleration - Acceleration = Net Force / Mass

The acceleration is (4 N - 4.9 N) / 5 kg.

5. Calculate the displacement: - Displacement = Initial Velocity × Time + (1/2) × Acceleration × Time^2 - Since the body is initially at rest, the initial velocity is zero.

The displacement is (1/2) × (4 N - 4.9 N) / 5 kg × (3 s)^2.

6. Calculate the work done: - Work = Force × Distance

The work done is 4 N × [(1/2) × (4 N - 4.9 N) / 5 kg × (3 s)^2].

Let's calculate the values.

Calculation

1. Calculate the weight of the body: - Weight = Mass × Acceleration due to Gravity - Weight = 5 kg × 9.8 m/s^2 - Weight = 49 N

2. Calculate the frictional force: - Frictional Force = Coefficient of Friction × Normal Force - Frictional Force = 0.1 × Weight - Frictional Force = 0.1 × 49 N - Frictional Force = 4.9 N

3. Calculate the net force: - Net Force = Applied Force - Frictional Force - Net Force = 4 N - 4.9 N - Net Force = -0.9 N

4. Calculate the acceleration: - Net Force = Mass × Acceleration - Acceleration = Net Force / Mass - Acceleration = -0.9 N / 5 kg - Acceleration = -0.18 m/s^2

5. Calculate the displacement: - Displacement = Initial Velocity × Time + (1/2) × Acceleration × Time^2 - Since the body is initially at rest, the initial velocity is zero. - Displacement = 0 × 3 s + (1/2) × -0.18 m/s^2 × (3 s)^2 - Displacement = 0 + (1/2) × -0.18 m/s^2 × 9 s^2 - Displacement = -0.81 m

6. Calculate the work done: - Work = Force × Distance - Work = 4 N × -0.81 m - Work = -3.24 J

Therefore, the work done by the applied force over a time period of 3 seconds is -3.24 Joules. The negative sign indicates that the work done is in the opposite direction of the applied force.

Please let me know if I can help you with anything else.