Is the Velocity Equation for SHM Correctly Derived Without Calculus?

In summary, the conversation discusses the equations for velocity and displacement when t = 0 for a particle in motion. The equation for displacement is x = A sin wt and for velocity is v = Aw cos wt. The value of t depends on the instant at which the particle is at equilibrium position. When t = 0, the equation for displacement is x = A and for velocity is v = 0. The amplitude A is equal to the maximum velocity Vo.
  • #1
ProPM
66
0
Hi :smile:

I am a bit lost with the equations for velocity:

I don't know Calculus yet, so my teacher just gave me the equation:

-wx0cos(wt) (w being omega)

He then said: v0 = wx0

and therefore, concluded: -v0cos(wt)

and then for when the displacement is maximum at time = 0: v0cos(wt)

Is this correct? I mean, I am obviously not doubting him but I am a bit confused plus my notes were not very organized on this day...

Thanks in advance
 
Physics news on Phys.org
  • #2
when t =0, ωt = 0 and cos(ωt) = 1

So vo = -xo*ω
 
  • #3
So the equation would be:

v0cos(wt)

and for sin, how would it work?
 
Last edited:
  • #4
The sign and the function sin or cos depends on the instant you are taking t=0. If t is taken zero when the particle is at the equilibrium position (x=0) than the equation for displacement will be x= A sin wt and that for velocity will be v = Aw cos wt

thus at extreme position wt = 90 deg, gives x = A and v = 0.
(A is amplitude and Aw = Vo, the maximum velocity)
 
  • #5


Hi there,

First of all, don't worry if you are not familiar with Calculus yet. The equations for Simple Harmonic Motion (SHM) can be quite complex, and it takes time to fully understand them. Let's break down the equations step by step to help you understand them better.

The equation you were given, -wx0cos(wt), is the equation for the displacement of an object undergoing SHM. The variable w represents the angular frequency, and x0 represents the amplitude (maximum displacement) of the motion. This equation can be derived using Calculus, but for now, it's important to understand that it represents the back and forth motion of an object in SHM.

Next, your teacher mentioned that v0 = wx0. This is the equation for the initial velocity of the object. In SHM, the initial velocity is equal to the product of the angular frequency and the amplitude. This means that the initial velocity is directly proportional to the amplitude of the motion.

Using this equation, your teacher concluded that the velocity equation for SHM is -v0cos(wt). This is because the velocity of an object in SHM is always changing, and it can be represented by the derivative of the displacement equation. Again, don't worry if you don't fully understand this yet, as Calculus is needed to fully grasp this concept.

Finally, when the displacement is maximum at time = 0, the velocity equation becomes v0cos(wt). This is because at this point, the object is moving at its maximum speed in the positive direction, and the cosine function represents this motion.

I hope this helps clarify the equations for you. Keep practicing and asking questions, and you will soon have a better understanding of SHM and its equations. Good luck!
 

Related to Is the Velocity Equation for SHM Correctly Derived Without Calculus?

1. What is SHM (simple harmonic motion)?

SHM is a type of periodic motion in which an object oscillates back and forth around a stable equilibrium position with a constant amplitude and period. It can be described mathematically using equations of motion.

2. What are the equations of motion for SHM?

The equations of motion for SHM are: x = A cos(ωt + φ), v = -Aω sin(ωt + φ), and a = -Aω^2 cos(ωt + φ), where x is the displacement, A is the amplitude, ω is the angular frequency, t is time, and φ is the phase angle.

3. How do you determine the period and frequency for SHM?

The period (T) of SHM is the time it takes for one complete oscillation and is calculated using the equation T = 2π/ω, where ω is the angular frequency. The frequency (f) is the number of oscillations per unit time and is calculated using the equation f = 1/T.

4. Can SHM equations of motion be applied to real-world situations?

Yes, SHM equations of motion can be applied to real-world situations such as the motion of a pendulum, a mass on a spring, and the vibrations of musical instruments. These systems can be approximated as simple harmonic oscillators and their motion can be described using the equations of motion.

5. How does amplitude affect SHM?

The amplitude of SHM is the maximum displacement from the equilibrium position. It affects the range of motion of the object and the maximum velocity and acceleration. The larger the amplitude, the greater the maximum velocity and acceleration will be. However, the period and frequency of SHM are not affected by the amplitude.

Similar threads

  • Classical Physics
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
5K
  • Introductory Physics Homework Help
Replies
3
Views
770
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
2K
Back
Top