Conceptual Standing Wave Question

AI Thread Summary
In a standing wave on a string, there are moments when the string appears completely flat, raising the question of the wave's energy at those times. It is suggested that despite the zero displacement, the wave is not stationary and retains kinetic energy due to its velocity. This indicates that energy is conserved in the system, even when the wave's amplitude is momentarily absent. The discussion confirms that the understanding of energy dynamics in standing waves is correct. Overall, the energy remains present in the form of kinetic energy, even during flat instances.
MyNewPony
Messages
30
Reaction score
0

Homework Statement



If you take snapshots of a standing wave on a string, there are certain instants when the string is totally flat.

What has happened to the energy of the wave at those instants?


The Attempt at a Solution



I'm assuming that nothing has happened to the energy. At that instant in time, even if the displacement of the wave is zero, it does not imply that the wave is stationary, therefore, it still has a velocity. Thus, there remains kinetic energy in the wave.

Am I on the right track?
 
Physics news on Phys.org
Hi MyNewPony,

MyNewPony said:

Homework Statement



If you take snapshots of a standing wave on a string, there are certain instants when the string is totally flat.

What has happened to the energy of the wave at those instants?


The Attempt at a Solution



I'm assuming that nothing has happened to the energy. At that instant in time, even if the displacement of the wave is zero, it does not imply that the wave is stationary, therefore, it still has a velocity. Thus, there remains kinetic energy in the wave.

Am I on the right track?

Yes, that sounds right to me.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How Do You Calculate the Energy of a Standing Wave?
Replies
21
Views
3K
Solving the wave equation for standing wave normal modes
Replies
11
Views
3K
Reflection of Waves and Formation of Standing Waves
Replies
6
Views
5K
I Mechanism of Energy Conservation in Zero-Amplitude Sum of EM Waveforms
Replies
12
Views
628
Calculating the length of a string from a standing wave
Replies
4
Views
2K
Calculating Mass of a Vibrating String Using Known Quantities
Replies
10
Views
2K
B Potential energy in standing wave compared to traveling wave
Replies
1
Views
1K
Understanding the definition of standing wave
Replies
7
Views
2K
Waves on a String -- Minimizing reflections from the far end (ring on a bar)
Replies
1
Views
2K
Sound Wave Interference and Finding the Path Differences with Diagrams
Replies
20
Views
5K

Hot Threads

Recent Insights

Back
Top