You calculate a rockets average velocity the same way you calculate the average velocity of anything else, a car, a running dog, or a stick floating on a stream. Velocity equals distance divided by time. It does not matter if your rocket traveled five thousand kilometers in one hour or if your car traveled 30 miles in one hour even if it stopped for gas along the way, you use the same formula.
Time and velocity
The instantaneous velocity is the limit of the average velocity, as the time interval tends to zero. If you are not familiar with limits, basically you make the time interval very small and calculate the average velocity.
Divide the net displacement by the time of travel.
Acceleration is the derivative of the velocity expression. If you have an equation for velocity, simply take the derivative of it and you will have an equation for the average acceleration.
I guess that would depend on what you want to calculate (the charge? the velocity? the average energy of the charges?), and what information is given.
Time and velocity
The instantaneous velocity is the limit of the average velocity, as the time interval tends to zero. If you are not familiar with limits, basically you make the time interval very small and calculate the average velocity.
Divide the net displacement by the time of travel.
Acceleration is the derivative of the velocity expression. If you have an equation for velocity, simply take the derivative of it and you will have an equation for the average acceleration.
It isn't clear what you mean by the "height of a velocity".
sharon sprinter changes her speed from 4.5m/s to 7.5m/s in the middle 1.5 seconds of a 100m race. what is her average velocity for this time period?
The average velocity in a particular direction = distance travelled in that direction / time taken. Velocity is a vector so the direction is important. If I go from A to B and then return to A my average velocity will be zero. My speed, on the other hand, will not be zero.
I guess that would depend on what you want to calculate (the charge? the velocity? the average energy of the charges?), and what information is given.
That is just not true! If you can calculate its average speed you should be able to calculate its speed at any point in time during its flight, including its final velocity.
You can calculate average speed by dividing the total distance travelled by the total time of travel. To go from speed to velocity, you would also need to determine the vector (direction of travel).
Calculate the average velocity for the objects.
If you are talking about rockets: T.ave = ((Isp)(delta Weight.ave))/(delta time.ave) That's one way to find it.