Speed - The measurement of distance travelled by a body per unit time is called speed.
• Speed (v) = Distance Travelled/Time Taken = s/t 
• SI unit = m/s (meter/second) 

Average Speed - The average speed of a body is the total distance travelled by the total time taken to cover this distance. 

  • Average speed= Total Distance travelled / Total Time taken 
  • EXAMPLE 1 - You walk 60 m at a speed of 3m/s and then run 140m at a speed of 7m/s along a straight track. Find the average speed?
  • EXAMPLE 2 - What will be the speed of body in m/s and km/hr if it travels 40 kms in 5 hrs ?