Is there an instantaneous angular acceleration for a conical pendulm?

In summary, for a conical pendulum, there is an instantaneous centripetal acceleration which is not equivalent to an instantaneous angular acceleration towards the center. The angle, defined as the angle between the string and the axis of symmetry, remains constant as the pendulum rotates, making it difficult to determine the direction of the acceleration. However, the changing radius vector and constant angular velocity indicate that there is indeed an acceleration towards the center.
  • #1
jason12345
109
0
For a conical pendulum, there is an instantaneous centripetal acceleration. Does this mean there is an instantaneous angular acceleration of the pendulum towards the center?
 
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  • #2
Can you define what your angle and center refer to?
 
  • #3
olivermsun said:
Can you define what your angle and center refer to?

The angle is between the string and the axis of symmetry the pendulum rotates around.
 
  • #4
I see, you're talking about a pendulum which swings about the center axis in a cone.

Your angle, as defined, rotates with the pendulum string and remains constant, so I would say "no."
 
  • #5
olivermsun said:
I see, you're talking about a pendulum which swings about the center axis in a cone.

Your angle, as defined, rotates with the pendulum string and remains constant, so I would say "no."

Thanks for your reply, although I disagree with it :) I could also argue that the radius of the circular motion is constant and so there isn't an acceleration towards the centre - but there is: v^2/r
 
  • #6
There is an acceleration (which happens to be toward the center) because the radius vector is not constant. Only the radius magnitude is constant.

As far as I can tell, the angular velocity is constant if defined around the axis of symmetry.
 
  • #7
olivermsun said:
There is an acceleration (which happens to be toward the center) because the radius vector is not constant. Only the radius magnitude is constant.

I think you mean velocity where you state radius.

As far as I can tell, the angular velocity is constant if defined around the axis of symmetry.

I agree that angular velocity is constant.
 
  • #8
jason12345 said:
I think you mean velocity where you state radius.

You're right. Change in radius vector per time (velocity) changes.
 
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  • #9
How does the radius vector not change? Doesn't it's magnitude stay the same, however the direction is changing?
 
  • #10
The radius does change (dr/dt is nonzero), so that there is a velocity, but he was talking about whether or not there is an acceleration. There is, since d^2/dt^2 = dv/dt is nonzero. A changing radius vector isn't enough to imply an acceleration, although it is enough that the magnitude stays the same while the direction is changing (as you say).
 

What is a conical pendulum?

A conical pendulum is a type of pendulum that moves in a circular motion rather than a back-and-forth motion. It consists of a weight suspended by a string or rod, which is attached to a fixed point above. As the weight swings, it traces out a cone shape instead of a straight line.

What is instantaneous angular acceleration?

Instantaneous angular acceleration is a measure of how quickly the angular velocity of an object is changing at a specific moment in time. In the case of a conical pendulum, it would refer to the rate at which the pendulum's angular velocity is changing as it moves along its circular path.

Is there a constant instantaneous angular acceleration for a conical pendulum?

No, there is not a constant instantaneous angular acceleration for a conical pendulum. The instantaneous angular acceleration will vary depending on the position of the pendulum along its circular path. It will be highest at the bottom of the cone and lowest at the top.

How is instantaneous angular acceleration different from average angular acceleration?

Instantaneous angular acceleration is a measure of the change in angular velocity at a specific moment in time, while average angular acceleration is a measure of the change in angular velocity over a period of time. Average angular acceleration takes into account the starting and ending angular velocities, whereas instantaneous angular acceleration only considers the velocity at a specific point.

Can instantaneous angular acceleration be negative for a conical pendulum?

Yes, instantaneous angular acceleration can be negative for a conical pendulum. This would occur when the pendulum is moving in the opposite direction of its current angular velocity, causing the velocity to decrease. This can happen when the pendulum is moving up along the cone, or when it reaches the top and begins to move back down.

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