In other words it is the rate at which an object changes its position from one place to another. Calculate the average velocity given the displacement and elapsed time. If and only if the acceleration is constant the average velocity is the same as the average of the final velocity and the initial velocity.
The average speed of a body in a certain time interval is the distance covered by the body in that time interval divided by time.
Average velocity formula - weighted average of velocities. This is 20 minus 30 so thats gonna be equal to negative 10 so this is equal to negative 10 meters over 300 seconds. That is we have to find the value of x_1 at time t_1 and x_2 at time t_2. The sum of the initial and final velocity is divided by 2 to find the average.