Period of Simple Harmonic Oscillators (Edexcel A Level Physics): Revision Note

Exam code: 9PH0

Katie M

Author

Katie M

Last updated

Period of a simple pendulum

  • A simple pendulum is: 

    • An object moving from side to side

    • Attached to a fixed point above 

  • The time period of a simple pendulum can also be calculated using this equation:

= 2πsquare root of l over g end root

  • Where: 

    • l is the length of the pendulum swing

    • is the strength of gravity on the planet on which the pendulum is set up

Worked Example

A child is sitting on a swing that is 200 cm long. What is the period of oscillation?

Answer:

Step 1: Convert length to meters

200 cm = 2 m

Step 2: Substitute the correct values

= 2πsquare root of l over g end root= 2πsquare root of fraction numerator 2 over denominator 9.81 end fraction end root=2.84 s 

Step 3: Confirm the answer

The time period of 1 oscillation of the swing is 2.84 s

Period of a Mass-Spring System

  • A mass-spring system means:

    • An object moving up and down 

    • On the end of a spring

13-3-mass-spring-example_edexcel-al-physics-rn
  • The equation for the restoring force in SHM F = - kx 

    • is the same as the equation for Hooke's Law

  • The time period, T can be calculated using the equation:

T = 2πsquare root of m over k end root

  • Where: 

    • m is the mass of the object on the end of the pendulum

    • k is the spring constant of the material the pendulum is made from

Observing the Motion of a Mass-Spring System

  • An experimental and graphical method can be used to observe the motion of a simple mass-spring system

    • Tie a pencil together with the mass and set the mass in free oscillations by displacing it downwards slightly

  • The oscillations will move the pencil up and down

    • On a piece of graph paper, allow the pencil to trace the path of the oscillations by pulling the paper sideways as the mass-spring system oscillates up and down

  • The oscillations will produce a curved, periodic graph

    • This will decrease in amplitude as the mass-spring system slows down

Mass and spring experiment, downloadable AS & A Level Physics revision notes

The motion of oscillator can be observed through a simple mass and spring system

👀 You've read 1 of your 5 free revision notes this week
An illustration of students holding their exam resultsUnlock more revision notes. It's free!

By signing up you agree to our Terms and Privacy Policy.

Already have an account? Log in

Did this page help you?

Katie M

Author: Katie M

Expertise: Physics Content Creator

Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.

Download notes on Period of Simple Harmonic Oscillators