02. Determination of unknown masses by using the principle of moments

  • 00:21 Why do we use the 70cm mark?
  • 01:22 What is the difference between weight and mass?
  • 01:29 What do we mean by the term systematic error?
  • 01:29 If the reading is stable but not zero can we still use the apparatus?
  • metre rule

  • clamp and stand

  • nail

  • 200 g mass and hanger

  • 150 g mass (covered in tape and labelled as W) and hanger

  • loops of thread

Hazard Risk Control measure

Nails have sharp ends

Nails can cause nasty cuts if they penetrate the skin.

Wear gloves and/or hold nail with pliers