Average speed formula

About the Average speed formula

The average speed of a body during a period of time is its mean value of speed. Because the speed of a moving body is not constant and varies over time, the formula for average speed is required. Even with changing speed, the total time and total distance traversed can be used, and we can get a single value to describe the entire motion using the average speed calculation.

Writing the formula

For the moving body, the average speed is given by the total distance covered by the body divided by the total time taken by the body to cover the distance.

Average speed = Total distance / Total time

Special cases

Case 1: : Let the body travel with the speed S₁ for time t₁ and S₁ for time t₁. Then total distance covered by the body is S₁t₁+S₂t₂ in total time t₁+t₂. Thus average speed is,

Case 2:Similarly, for 'n' different speeds, S₁,S₂,S₃,S₄,……..,S_n are given for 'n' respective individual time intervals, t₁,t₂,t₃,...tn respectively, then average speed is given as,

Case 3:Average speed when body covers different distances, d₁,d₂,d₃,...d_n in different intervals of time, t₁,t₂,t₃,...t_n repectively is given as,

Case 4:Average speed when body travels with different speeds, S₁,S₂,S₃,S₄,……..,S_n and different distances, d₁,d₂,d₃,...d_n respectively is given as:

Case 5:: Average speed formula when body travels with two or more speeds (S₁,S₂,S₃,S₄,……..,S_n) for same amount of time (t₁=t₂=t₃=...t_n=t) is given as: