IB DP Physics: SL复习笔记2.1.1 Distance & Displacement

• Distance is a measure of how far an object travels
• It is a scalar quantity - in other words, the direction is not important

The athletes run a total distance of 300 m

• Consider a 300 m race
• From start to finish, the distance travelled by the athletes is 300 m

Displacement

• Displacement is a measure of how far something is from its starting position, along with its direction
• It is a vector quantity - it describes both magnitude and direction

The athletes run a total distance of 300 m, but end up 100 m from where they started

• Consider the same 300 m race again
  • The athletes have still run a total distance of 300 m (this is indicated by the arrow in red)
  • However, their displacement at the end of the race is 100 m to the right (this is indicated by the arrow in green)
  • If they had run the full 400 m, their final displacement would be zero