Physics speed notes gceo level

Speed is the distance moved per unit time.

• SI unit is metre per second (ms−1)
• Scalar quantity
• Equation: Speed=dt, where d is distance travelled and t is time taken
• Average speed can be calculated using totaldistancetravelledtotaltimetaken
• Instantaneous speed is the speed at any instant
  1. Measured by a speedometer

A speedometer measures the instantaneous speed

Velocity (v) of an object is the rate of change of displacement with respect to time.

• SI unit is metre per second (ms−1)
• Vector quantity
• The magnitude of velocity is speed
• v=st, where s is displacement and t is time taken

As velocity is a vector quantity, you have to specify its magnitude and direction to completely describe it.