Math Problem Statement

A mass π‘š, suspended by a spring of stiffness π‘˜, is set into simple harmonic motion. The period of oscillation is given by: t=2√(Ο€&m/k)

Using dimensional analysis, demonstrate that the period of oscillation does, indeed, have units of time.

Solution

To verify that the period of oscillation has units of time, we can apply dimensional analysis. The equation provided is:

t=2Ο€mkt = 2 \sqrt{\frac{\pi m}{k}}

Step 1: Identify the dimensions of the parameters

We need to break down the dimensional units for each parameter involved in the equation:

  1. tt - Time period (we need to verify that this results in units of time).
  2. mm - Mass, which has the dimension of [M] (mass).
  3. kk - Spring constant (stiffness), which is related to force per unit displacement. From Hooke's law, F=kxF = kx, where FF is force and xx is displacement.
    • The dimension of force is [M][L][T]^{-2}, where:
      • [M] = mass,
      • [L] = length,
      • [T] = time.
    • Displacement xx has the dimension of length [L].
    • Therefore, the spring constant kk has the dimension of force per length:
      [ [k] = \frac{[M][L][T]^{-2}}{[L]} = [M][T]^{-2} ]
  4. Ο€\pi - Dimensionless constant, so it has no dimensions.

Step 2: Analyze the right-hand side of the equation

We need to focus on the argument under the square root, mk\frac{m}{k}.

[ \frac{m}{k} = \frac{[M]}{[M][T]^{-2}} = [T]^2 ]

Step 3: Apply the square root

Taking the square root of the result, we get:

[ \sqrt{\frac{m}{k}} = \sqrt{[T]^2} = [T] ]

Step 4: Check the overall dimensions of the equation

Since the expression mk\sqrt{\frac{m}{k}} has the dimension of time [T], the period of oscillation tt must also have units of time:

t=2mkβ€…β€ŠβŸΉβ€…β€Št has units of [T]t = 2 \sqrt{\frac{m}{k}} \quad \implies \quad t \ \text{has units of} \ [T]

Thus, by dimensional analysis, we have confirmed that the period of oscillation does indeed have units of time.


Would you like more details or have any questions?

Here are 5 related questions:

  1. What factors affect the period of oscillation in simple harmonic motion?
  2. How does the spring constant kk influence the period?
  3. Can dimensional analysis be applied to other physics problems? How?
  4. What is the significance of Ο€\pi in the formula?
  5. How would the period change if the mass mm is doubled?

Tip: Dimensional analysis is a powerful tool for checking the consistency of equations, especially when you're unsure of a derived formula.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Dimensional Analysis
Simple Harmonic Motion
Units of Measurement

Formulas

t = 2√(Ο€m/k)
[k] = [M][T]^{-2}
t = 2√(m/k)

Theorems

Hooke's Law

Suitable Grade Level

Grades 10-12