Understanding Simple Harmonic Motion: The Role of Frequency in Wave Equations

In summary, the conversation discusses the derivation of the equation of simple harmonic motion (SHM) and the use of a proportionality constant to make the force and displacement equal. The question is whether there is a derivation that shows the constant is equal to the frequency of the SHM. The expert suggests that this is not possible due to units, but for a system with unit mass, the constant is equal to the frequency squared. The concept of SHM is also briefly discussed.
  • #1
Shan K
73
0
I was reading a book on wave and found that when they derive the equation of shm from the equation force varies with negetive displacement , they had taken a propotionality constant to make the force and displacement equal and they had taken frequency of the shm as the constant . So my question is , is there any derivation which can show that the constant is the frequency of the shm .
 
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  • #2
It would help if you told us what the system was.
Spring and mass vertical or horizontal?
Pendulum?
?

The basis of SHM is always that the restoring force is proportional to the displacement (from the mean position). Since the force tends to return the system to the mean position is acts in the opposite direction to the displacement so one is negative.
 
  • #3
It was for pendulum
 
  • #4
I am not sure what your question is; anyway, the equations of shm could be derived by applying the principle of conservation of mechanical energy.
 
  • #5
Let me show u the derivation .
We know that for shm


force varies as negetive displacement


therefore,
force equal to some constant times negetive displacement


they said that this constant is equal to the frequency of the shm . I want to know how ?
( sorry for writing all the equation in words cus my mobile doesn't support to write equations with some special charecters . )
 
  • #6
Sorry to ask another question but I don't want to post something different from your course.

What definition of SHM are you using?
 
  • #7
Shan K said:
So my question is , is there any derivation which can show that the constant is the frequency of the shm .

No, because the units mean that can't possibly be correct.

But for a system with unit mass, the constant is equal to the frequency squared (frequency measured in radians/second, not Hz).

This should be explained in any textbook or website about the dynamics of single degree of freedom (SDOF) systems.

For a pendulum, the "unit mass" part doesn't matter, since the force (i.e. weight) is proportional to the mass.
 
  • #8
Studiot said:
Sorry to ask another question but I don't want to post something different from your course.

What definition of SHM are you using?

i don't have studied any kind of definition on shm . What i have studied is some properties of that like it has a restoring force
 

FAQ: Understanding Simple Harmonic Motion: The Role of Frequency in Wave Equations

What is simple harmonic motion?

Simple harmonic motion is a type of periodic motion in which an object oscillates back and forth between two points, with a constant cycle of acceleration and deceleration. This type of motion can be seen in various phenomena, such as the swinging of a pendulum, the vibration of a guitar string, or the motion of a mass attached to a spring.

What is the equation for simple harmonic motion?

The equation for simple harmonic motion is x = A sin(ωt + φ), where x is the displacement from the equilibrium position, A is the amplitude of the motion, ω is the angular frequency, and φ is the phase angle. This equation describes the position of the object at any given time during the motion.

What is the relationship between frequency and period in simple harmonic motion?

The frequency and period of simple harmonic motion are inversely proportional. This means that as the frequency increases, the period decreases, and vice versa. The frequency is the number of cycles per unit of time, while the period is the time it takes for one complete cycle.

How does damping affect simple harmonic motion?

Damping refers to the gradual decrease in amplitude of a simple harmonic motion due to external forces, such as friction. The amount of damping can affect the frequency and period of the motion, as well as the amplitude. In heavily damped systems, the motion may eventually come to a stop, while in lightly damped systems, the motion may continue indefinitely.

What are some real-life examples of simple harmonic motion?

Simple harmonic motion can be observed in many natural and man-made systems. Some examples include the swinging of a child on a swing, the motion of a diving board after a diver jumps off, the vibrations of a tuning fork, and the motion of a car's suspension system. It can also be seen in the movement of sound waves and light waves.

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