Simple harmonic motion and positive constant w^2?

In summary, the Equation of simple harmonic motion is defined by taking the origin as a fixed point and the line of motion as the x axis. The acceleration is represented by a negative constant multiplied by the square of w, where w is a positive constant. This is because acceleration is derived from the double derivative of the equation for displacement in SHM, and in order for the constant to be negative, it must be expressed as a square. This is a common practice in physics when a real quantity is required to be positive.
  • #1
gunparashar
7
0
in defining the Equation of simple harmonic motion taking origin as fixed point and the line of motion as x axis. a(acceleration) = - w^2 * x. where w^2 is positive constant. what is the reason behind taking square of w as constant not just w?
 
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  • #2
Because it is not just 'taken'. Acceleration is the rate of change of velocity. Velocity is rate of change of displacement. So the double derivative of the equation for displacement in SHM gives you the equation for acceleration. During the process of deriving it, you get an w^2.
Here's how it is done: http://physicscatalyst.com/wave/shm_0.php
 
  • #3
Another way of looking at is:
SHM is where a restoring force always acts towards the origin. So when x is positive the force has to be in the negative direction, when negative the force has to be in the positive direction.
The acceleration will be in the direction of the force.
So when x is positive the force is negative, when x is negative the force is positive.
For acceleration = - const X x to keep the minus the constant MUST be positive. That means it must be a square (guaranteed to be positive).

More generally when you require a real quantity to be positive - express it as a square i.e x2
When required to be negative - express it as the negative of a square i.e. - x2
 
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1. What is simple harmonic motion?

Simple harmonic motion refers to the back-and-forth movement of an object or system that is caused by a restoring force that is directly proportional to the displacement from the equilibrium position. This type of motion is characterized by a sinusoidal (or wave-like) pattern.

2. What is the formula for simple harmonic motion?

The formula for simple harmonic motion is x(t) = A sin(ωt + φ), where x is the displacement, t is time, A is the amplitude, ω is the angular frequency, and φ is the phase angle.

3. How does positive constant w^2 affect simple harmonic motion?

The positive constant w^2, also known as the angular frequency squared, determines the speed of the oscillations in simple harmonic motion. A larger value for w^2 means a higher frequency of oscillations, while a smaller value means a lower frequency. In addition, the value of w^2 also affects the amplitude of the oscillations.

4. What is the relationship between simple harmonic motion and energy?

Simple harmonic motion involves the exchange of potential and kinetic energy as the object or system moves back and forth. At the equilibrium position, the object has maximum potential energy and zero kinetic energy. As it moves away from equilibrium, the potential energy decreases and the kinetic energy increases. At the turning points, the potential energy is zero and the kinetic energy is at its maximum. This energy exchange continues as the object oscillates.

5. How is simple harmonic motion related to real-life phenomena?

Simple harmonic motion can be observed in many real-life phenomena, such as the motion of a pendulum, the vibrations of a guitar string, and the movement of a mass-spring system. It is also used to model natural phenomena such as the motion of tides, ocean waves, and sound waves.

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