Angular momentum conservation: determine velocity of impactor

In summary, a uniform rod of length L and mass M is hanging at rest from a frictionless pivot. A particle of mass m moving perpendicularly to the rod at speed v hits the rod at a distance 0.8L below the pivot and sticks to it. After the collision, the maximum angle between the rod and the vertical is 90 deg. The equation for solving this problem involves finding an equation for t in terms of moment of inertia, mass, or radius. ωf is the arclength equation S=rθ divided by time, where theta is π/2 (90 deg) and r is L.
  • #1
Vitani11
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Thread title changed to reflect problem description

Homework Statement


A uniform rod of length L and mass M hangs at rest from a frictionless pivot. The rod is hit a distance 0.8L below the pivot by a particle of mass m moving perpendicularly to the rod at speed v; the particle sticks to the rod. Following the collision, the maximum angle between the rod and the vertical is 90 deg. What is v?

Homework Equations


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The Attempt at a Solution


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  • #2
This is where I'm at. I need another equation for t in terms of moment of inertia, mass, or radius. At least I am about 80% sure that is all I need left to solve this.
 

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  • #3
In case you're wondering where ωf came from: It is the arclength equation S=rθ divided by time, where theta was given as π/2 (90 deg) and r is L.
 

What is angular momentum conservation?

Angular momentum conservation is a fundamental principle in physics that states that the total angular momentum of a system remains constant, as long as there are no external torques acting on the system.

How is angular momentum conserved?

Angular momentum is conserved through the conservation of both linear momentum (mass x velocity) and moment of inertia (mass x radius squared). This means that if one component of angular momentum changes, the other component must change in the opposite direction in order to keep the total angular momentum constant.

What is the equation for angular momentum conservation?

The equation for angular momentum conservation is L = Iω, where L is the angular momentum, I is the moment of inertia, and ω is the angular velocity. This equation shows that angular momentum is directly proportional to both moment of inertia and angular velocity.

How can angular momentum conservation be applied to determine the velocity of an impactor?

To determine the velocity of an impactor using angular momentum conservation, we can use the equation L = mvr, where m is the mass of the impactor, v is its velocity, and r is the distance from the center of rotation. By setting the initial angular momentum equal to the final angular momentum, we can solve for the velocity of the impactor.

What are some real-world applications of angular momentum conservation?

Angular momentum conservation has many practical applications, such as in understanding the motion of spinning objects like tops and gyroscopes, predicting the behavior of celestial bodies in space, and even in sports like figure skating and gymnastics where athletes use their body's angular momentum to perform impressive maneuvers.

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