SHM- Problem with negative signs

In summary, negative signs can cause problems in Simple Harmonic Motion (SHM) by altering the direction or phase of the motion. They can affect the equations of SHM by changing the sign of the angular frequency, leading to incorrect calculations. Common mistakes related to negative signs in SHM problems include forgetting to account for them and using the wrong sign in equations. To avoid these mistakes, it is important to carefully analyze the problem and use the correct sign in equations. While negative signs are not always a problem in SHM, it is important to be aware of their potential effects and use them correctly in calculations.
  • #1
annms
16
3
I have problems understanding the use of negative signs in SHM. ie. mx''=-kx

Why is there a negative sign for the constant k and what does the negative sign mean?
 
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  • #2
The negative sign in Hooke's law tells you that the force is opposite to the displacement from equilibrium. If x is positive, then the force is negative. And vice versa.

The negative sign is not part of the constant k.
 

1. What is SHM and why are negative signs a problem in this concept?

SHM stands for Simple Harmonic Motion, which refers to the repetitive back and forth motion of a system around an equilibrium point. Negative signs become a problem in SHM because they can alter the direction or phase of the motion, leading to incorrect calculations or predictions.

2. How do negative signs affect the equations of SHM?

Negative signs can change the sign of the angular frequency (ω), which is a crucial component in the equations of SHM. This can lead to an incorrect determination of the period or amplitude of the motion, as well as the displacement and velocity at any given time.

3. What are some common mistakes related to negative signs in SHM problems?

One common mistake is forgetting to account for the negative sign in the angular frequency when solving for the period or amplitude. Another mistake is using the wrong sign in the displacement or velocity equations, leading to incorrect values for these variables.

4. How can we avoid making mistakes with negative signs in SHM problems?

To avoid mistakes, it is important to carefully analyze the given problem and identify any negative signs in the equations. Pay attention to the direction of the motion and use the correct sign in the equations. It can also be helpful to double check calculations and solutions to ensure they make sense in the context of the problem.

5. Are negative signs always a problem in SHM?

No, negative signs are not always a problem in SHM. In some cases, they may represent a change in direction or phase of the motion. However, when solving equations or making calculations, it is important to be aware of the potential effects of negative signs and use them correctly to avoid errors.

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