How Does a Pendulum Swing Conserve Momentum?

In summary, the conversation discusses the concept of conservation of angular and linear momentum in a pendulum swing. The conclusion is that neither momentum is conserved in a pendulum swing because the values at the top and bottom of the swing are not the same.
  • #1
Kaxa2000
71
0
Does a pendulum swing demonstrate angular momentum, linear, both, or neither?
 
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  • #2
What do you think it is and why?
 
  • #3
I believe its both because during the swing the bob has a linear momentum vector with the swing. This creates an angular momentum vector out of the plane of the pendulum swing. Once it reaches its max height during the swing the force of gravity causes it to fall back the other way creating a torque vector perpendicular to plane of swing.

I'm not sure if this is completely right...I ask for confirmation
 
  • #4
Kaxa2000 said:
I believe its both because during the swing the bob has a linear momentum vector with the swing. This creates an angular momentum vector out of the plane of the pendulum swing. Once it reaches its max height during the swing the force of gravity causes it to fall back the other way creating a torque vector perpendicular to plane of swing.

I'm not sure if this is completely right...I ask for confirmation

then yes, it has both linear and angular momentum.
 
  • #5
Is that the same thing as saying a pendulum swing conserves angular and linear momentum??
 
  • #6
Let's see. At the top of the pendulum's swing (when v=0), what's the linear & angular momentum of the bob? At the bottom of the swing, what's the linear & angular momentum of the bob? Are the two the same?
 
  • #7
No

Angular momentum : L = r x p

At top of swing when v = 0

p = 0
&
L = rAt bottom of swing
p = mv

L = r x p

So they are not conserved??
 
Last edited:
  • #8
Well, angular momentum at the top of the swing is actually 0 because p=0 and L=r x p. The conclusion is correct, however: neither is conserved.
 
  • #9
Kaxa2000 said:
No

Angular momentum : L = r x p

At top of swing when v = 0

p = 0
&
L = r


At bottom of swing
p = mv

L = r x p

So they are not conserved??

Your question asked whether it has angular momentum and/or linear momentum, not whether it was conserved or not.
 
  • #10
x is the cross product in this case.

Is r cross product 0 = 0?

Sorry I kind of forgot cross product ...so I'm not surerockfreak, sorry maybe I shouldve restated it in the actual post but the topic title is "pendulum swing conserves what?"
 
  • #11
How does it show that neither are conserved? Is it because the result is not the same at the top of the swing and the bottom of the swing in both cases?
 

FAQ: How Does a Pendulum Swing Conserve Momentum?

What is the concept of conservation of pendulum swing?

The conservation of pendulum swing refers to the principle that the total amount of energy in a swinging pendulum system remains constant. This means that as the pendulum moves back and forth, the energy is continuously converted between potential and kinetic energy, but the total amount remains the same.

How does the length of a pendulum affect its conservation of swing?

The length of a pendulum does not affect its conservation of swing. This is because the conservation of energy in a pendulum system is dependent on the mass and velocity of the pendulum, not its length.

Does the weight of the pendulum affect its conservation of swing?

Yes, the weight of the pendulum does affect its conservation of swing. A heavier pendulum will have more kinetic energy and therefore will have a larger swing amplitude. However, the total amount of energy in the system will remain constant.

What factors can impact the conservation of pendulum swing?

The conservation of pendulum swing can be impacted by factors such as air resistance, friction at the pivot point, and external forces such as pushing or pulling on the pendulum. These factors can cause the pendulum to lose some of its energy and affect its swing amplitude.

Why is the concept of conservation of pendulum swing important?

The concept of conservation of pendulum swing is important because it is a fundamental principle in physics that applies to many systems and helps to explain the behavior of objects in motion. It also allows us to predict the motion of a pendulum and understand its energy transformations.

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