BBC Learning Zone Clips


Application of balanced forces

Application of balanced forces
Key Info
  • Application of balanced forces
  • Duration: 04:16
  • Investigating what makes a comfortable chair by changing the net force exerted on a seat and observing the change in pressure. The presenter talks to an ergonomist about seat comfort. First they measure the up and down force when sitting in different chairs. They then plot the pressure profile across the area of the presenter's bottom when sitting in a car seat. They find there are high pressure points and so repeat the test with a slightly different seating position in which the upper body leans back and the legs are stretched out. This evens out the pressure on the sitter.
  • Subject:



    Phys: Forces - Contact and Non-contact

  • Keywords: forces, balanced forces, resultant force, pressure
Ideas for use in class
  • Brings together the ideas of finding the resultant or net force and how this affects the pressure exerted on different seats. Use in forces topic as an example of finding the resultant force for stationary objects. Use in pressure and moments topic as an example of calculating pressure. G&T pupils could estimate the pressure they exert on their chairs.
Background details
  • Clip language : English
  • Aspect ratio : 4x3

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