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Grade 12Mechanics

four 2kg masses are connected by 0.25m spokes to an axel.A force of 24N acts on a lever 0.5m long to produce angular acceleration ∂.find the angular acceleration

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8 Years agoGrade 12
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To find the angular acceleration (∂) of the system, we need to apply some principles from rotational dynamics. Let's break this down step by step.

Understanding the System

We have four 2 kg masses connected to an axle by spokes that are 0.25 m long. The force of 24 N is applied at the end of a lever that is 0.5 m long. The first step is to determine the torque produced by the applied force.

Calculating Torque

Torque (τ) is calculated using the formula:

  • τ = F × r

Where:

  • F is the force applied (24 N)
  • r is the distance from the pivot point to where the force is applied (0.5 m)

Plugging in the values:

  • τ = 24 N × 0.5 m = 12 N·m

Finding the Moment of Inertia

Next, we need to calculate the moment of inertia (I) of the system. The moment of inertia for point masses is given by:

  • I = Σ(m × r²)

In our case, each mass is 2 kg and is located at a distance of 0.25 m from the axle. Since there are four masses, we calculate:

  • I = 4 × (2 kg × (0.25 m)²)
  • I = 4 × (2 kg × 0.0625 m²) = 4 × 0.125 kg·m² = 0.5 kg·m²

Applying Newton's Second Law for Rotation

Now, we can use Newton's second law for rotation, which states:

  • τ = I × ∂

We can rearrange this to solve for angular acceleration (∂):

  • ∂ = τ / I

Substituting the values we calculated:

  • ∂ = 12 N·m / 0.5 kg·m² = 24 rad/s²

Final Result

The angular acceleration (∂) of the system is 24 rad/s². This means that the system will accelerate at this rate in terms of its rotational motion when the 24 N force is applied.