Section 6.8: Applications of SHM

Simple Harmonic Motion (SHM) is not just a mathematical model — it has many real-world applications in science, engineering, and technology. Systems that approximate SHM are useful because their motion is predictable and well understood.

Common Applications:
  • Pendulums: Used in clocks for timekeeping.
  • Mass-spring systems: Basis for vibration absorbers and vehicle suspensions.
  • Electromagnetic oscillations: LC circuits in radios and electronics.
  • Seismology: Earthquake waves modeled as oscillatory motion.
  • Medical applications: Imaging and resonant scanning devices.

Example 1

A grandfather clock uses a pendulum of length \( L = 0.994 \,\text{m} \). Show that its period is close to 2.00 s, making it suitable for timekeeping.

Period of a simple pendulum:

\[ T = 2\pi \sqrt{\frac{L}{g}} \]

Substitute values:

\[ T = 2\pi \sqrt{\frac{0.994}{9.8}} \approx 2.00 \,\text{s} \]

This matches the required timekeeping interval.

Practice Problems

  1. Explain how car suspension systems rely on SHM principles.
  2. A child’s swing of length 2.5 m is displaced slightly and released. Find its approximate period.
  3. Why are LC circuits considered oscillatory systems similar to SHM?
  4. Describe one way SHM applies in medical imaging technology.
  5. Discuss why an understanding of SHM is important in designing earthquake-resistant buildings.