.2 speed

• Speed does not involve direction. Speed is a scalar quantity.
• The speed of a moving object is rarely constant. When people walk, run or travel in a car their speed is constantly changing.
• The speed at which a person can walk, run or cycle depends on many factors including: age, terrain, fitness and distance travelled.
• Typical values may be taken as:

  walking ̴ 1.5 m/s

  running ̴ 3 m/s

  cycling ̴ 6 m/s
• It is not only moving objects that have varying speed. The speed of sound and the speed of the wind also vary
• A typical value for the speed of sound in air is 330 m/s.
• distance =


  distance travelled = speed × time
• s  = v t distance,

  s, in metres, m

  speed, v, in metres per second, m/s

  time, t, in seconds, s