Rod and gravity pendulum (TM 161)

Rod and gravity pendulum (TM 161)

investigation of pendulum swings



  • Pendulums perform oscillations. Gravity produces the restoring moment.
  • We distinguish between mathematical and physical pendulums.
  • A mathematical pendulum describes an idealised gravity pendulum.
  • In physical pendulums, the shape and size of the pendulum body is taken into account.
  • Both are theoretical models for the description of a real pendulum.
  • The TM 161unit is used to study pendulum swings.
  • A gravity pendulum (mathematical pendulum) and a rod pendulum (as a physical pendulum) are compared to each other.
  • The unit contains a metal rod with a movable auxiliary mass as the rod pendulum.
  • The suspension point can be adjusted on the knife-edge bearing of the pendulum.
  • The length of the gravity pendulum can be easily changed using a clamping device.
  • The experimental unit is designed to be fixed to a wall.

Technical Details:


  • experiments on pendulum swings, comparison of physical and mathematical pendulums
  • rod pendulum as physical pendulum, made of metal and mounted on knife-edge bearing
  • knife-edge bearing mounted to slide on the rod to effectively vary the pendulum length
  • weight for the rod pendulum, sliding
  • gravity pendulum as a mathematical pendulum
  • adjustable length of the gravity pendulum
  • stopwatch to measure the oscillation period
  • bracket for wall mounting

Technical Data:

  • Gravity pendulum:
    • length: up to 2000mm
    • nylon rope
  • weight:
    • diameter: 50mm
    • mass: 0,52kg
  • Rod pendulum:
    • length:1000mm
    • diameter: 8mm
    • mass: 0,39kg
  • pendulum weight:
    • diameter: 50mm
    • mass: 0,49kg
  • Stopwatch: 1/100s
  • Measuring tape: 3m

Dimensions & Weight:

  • L x W x H: 250x80x2000mm
  • Weight: approx. 5kg

Learning Objections/Experiments:

  • oscillation period of gravity and rod pendulum
  • determine centre of gravity on the rod pendulum
  • reduced pendulum length and centre of inertia of the rod pendulum

Scope of Delivery:

  • 1 experimental unit
  • 1 set of instructional material


  • comparing physical and mathematical pendulums

Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.