Find Angular Acceleration: Torque & Rotational I

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SUMMARY

The discussion focuses on calculating angular acceleration for a system involving two masses (m and 2m) attached to a rigid massless rod on a frictionless table. The applied force F generates a rotational acceleration expressed as kF/(mL), where k is to be determined. The center of mass is located at 2/3 L below mass m. The user seeks clarification on calculating torque and moment of inertia (I) to solve for angular acceleration.

PREREQUISITES
  • Understanding of torque and its calculation using the formula τ = r × F
  • Knowledge of moment of inertia (I) for rigid bodies
  • Familiarity with angular acceleration and its relationship to torque
  • Basic principles of center of mass in multi-body systems
NEXT STEPS
  • Study the calculation of moment of inertia for composite systems
  • Learn about the relationship between torque and angular acceleration in rotational dynamics
  • Explore the concept of center of mass and its implications in rotational motion
  • Review examples of torque calculations in physics problems
USEFUL FOR

Students studying physics, particularly those focusing on rotational dynamics, mechanics, and torque calculations. This discussion is beneficial for anyone tackling problems involving angular acceleration and moment of inertia.

wushumaster
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Homework Statement


The figure shows a view from above of two objects attached to the end of a rigid massless rod at rest on a frictionless table. Imagine a vertical rod, on the top end is a mass of m, an the bottom is a mass of 2m. The length of the rod is L and L/4 down from m (at top), a horizontal and rightward force is applied. When this F is applied, the resulting rotational acceleration of the rod about its center of mass is kF/(mL).

Homework Equations


What is K?

The Attempt at a Solution


So I found the center of mass as 2/3 L below mass m. but I don't understand how we can get torque (like I know its r cross F), but.. We can use torque=I times angular acceleration. But i got I wrong. HELP! please!
 
Physics news on Phys.org
oh! is it just because torque equals r cross f and that means it equals 2/3 L- 1/4 L?
 

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