Dynamics Coursework; Angular Velocity, Springs, Force

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SUMMARY

The discussion focuses on a physics problem involving a flat circular disc rotating at a constant angular velocity of 240 RPM, with sliding blocks and springs. The blocks, each weighing 0.5 kg and positioned at 25 mm, are subject to a spring force with a stiffness of 400 N/m. The key tasks are to determine the displacement value for each spring and calculate the normal force exerted by the slot on the blocks. The analysis involves understanding the fictitious radial force \(m r \omega^2\) and the balance of forces in a rotating reference frame.

PREREQUISITES
  • Understanding of angular velocity and its units (RPM)
  • Knowledge of spring mechanics, specifically Hooke's Law
  • Familiarity with forces in a rotating reference frame
  • Basic principles of dynamics and equilibrium
NEXT STEPS
  • Study the effects of angular velocity on forces in rotating systems
  • Learn about Hooke's Law and its applications in dynamic systems
  • Explore the concept of fictitious forces in non-inertial reference frames
  • Investigate the calculations for normal forces in constrained motion scenarios
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DTskkaii
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Question:
The flat circular disc rotates about a vertical axis through O with a constant angular velocity of 240rpm. Prior to rotation, each of the 0.5kg sliding blocks has the position x=25mm with no force in its attached spring. Each spring has a stiffness of 400N/m, Neglect any friction between the blocks and the slots, and neglect the mass of the springs.

(a) Determine the value of x for each spring
(b) Calculate the normal force N exerted by the side of the slot on the block

I have attached the diagram.

Relevant equations
Not yet completely sure. If someone knows of a resource towards rotational velocity, that would be helpful, but I will update this section as soon as I have identified appropriate equations.
The attempt at a solution
As per above, I will upload something as soon as I can get a solid attempt down. I'm honestly incredibly lost on this question, it just seems like there are so many aspects happening at once.
 

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DTskkaii said:
Question:
The flat circular disc rotates about a vertical axis through O with a constant angular velocity of 240rpm. Prior to rotation, each of the 0.5kg sliding blocks has the position x=25mm with no force in its attached spring. Each spring has a stiffness of 400N/m, Neglect any friction between the blocks and the slots, and neglect the mass of the springs.

(a) Determine the value of x for each spring
(b) Calculate the normal force N exerted by the side of the slot on the block

I have attached the diagram.

Relevant equations
Not yet completely sure. If someone knows of a resource towards rotational velocity, that would be helpful, but I will update this section as soon as I have identified appropriate equations.
The attempt at a solution
As per above, I will upload something as soon as I can get a solid attempt down. I'm honestly incredibly lost on this question, it just seems like there are so many aspects happening at once.

In the rotating reference frame you have the following forces acting on the left hand block (the motion of the other is the same after the appropriate transformation):

A radially outward (ficticious) force \(m r \omega^2 \).

The normal reaction force from the side of the slot \(N\) in the +ve horizontal direction.

The spring force \(k(x-25)\) in the -ve vertical direction.

Since the block is constrained to move in the vertical by the slot the normal reaction will always balance the horizontal component of the radial force.

CB
 

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