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Grade 12Modern Physics

An event organizer pushes a 300-N container along a level floor at constant speed with a
force directed 45° below the horizontal. If the coefficient of the kinetic friction is 0.3, how
much work does the event organizer do on the container?

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5 Years agoGrade 12
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1 Answer

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ApprovedApproved Tutor Answer11 Months ago

To determine the work done by the event organizer on the container, we first need to analyze the forces acting on the container and how they relate to the work done. The work done is calculated using the formula:

Understanding Work Done

Work is defined as the product of the force applied in the direction of motion and the distance over which that force is applied. Mathematically, it can be expressed as:

Work (W) = Force (F) × Distance (d) × cos(θ)

Here, θ is the angle between the force and the direction of motion. In this case, the force is applied at a 45° angle below the horizontal, which means we need to consider this angle when calculating the work done.

Breaking Down the Forces

Given that the container has a weight of 300 N, we can start by calculating the normal force acting on it. The normal force is affected by the vertical component of the applied force. The applied force can be broken down into its horizontal and vertical components:

  • Horizontal Component (F_horizontal): F × cos(θ)
  • Vertical Component (F_vertical): F × sin(θ)

Let’s denote the applied force as F. Since the force is directed at 45°, we have:

  • F_horizontal = F × cos(45°) = F × (√2/2)
  • F_vertical = F × sin(45°) = F × (√2/2)

Calculating the Normal Force

The normal force (N) can be calculated by considering the weight of the container and the vertical component of the applied force:

N = Weight - F_vertical

Since the weight is 300 N, we have:

N = 300 N - F × (√2/2)

Frictional Force

The frictional force (f_friction) opposing the motion can be calculated using the coefficient of kinetic friction (μ_k) and the normal force:

f_friction = μ_k × N

Substituting the expression for N, we get:

f_friction = 0.3 × (300 N - F × (√2/2))

Equilibrium Condition

Since the container is moving at a constant speed, the net force in the horizontal direction must be zero. Therefore, the horizontal component of the applied force must equal the frictional force:

F_horizontal = f_friction

Substituting the expressions we derived:

F × (√2/2) = 0.3 × (300 N - F × (√2/2))

Solving for the Applied Force

This equation can be solved for F, but for the purpose of calculating work, we can simplify our approach. Since we need the work done, we can focus on the horizontal component of the force and the distance moved.

Calculating Work Done

Assuming the distance (d) the container is pushed is known, the work done by the organizer can be calculated as:

W = F_horizontal × d

Since we know that:

F_horizontal = F × (√2/2)

We can substitute this into our work formula:

W = (F × (√2/2)) × d

Final Calculation

To find the exact value of work done, we would need the distance (d) over which the container is pushed. If we assume a distance, we can plug that value into the equation to find the work done.

In summary, the work done by the event organizer on the container depends on the horizontal component of the force applied and the distance moved. By breaking down the forces and understanding the relationships between them, we can effectively calculate the work done in this scenario.