Constant Speed

Constant speed is when you keep the same speed over a period of time.

An example is if you stay going 45 miles per hour and stay going 45 miles per hour for 5 minutes.

Constant speed stays constant like clouds stay in the atmosphere. The comparison is that they both stay in the same place and they both stay in the same area.

Variable Speed

Variable speed is where your speed changes over periods of time.

An example is if you are in a 45 mile zone and then you move into a 35 mile zone.

Variable speed changes like seasons changes. The comparison is that the variable speed is the type of speed that changes, and seasons change throughout the year.

Average Speed

Average speed is the total distance traveled divided by the total time elapsed(taken up).

An example is if you do 50 miles per hour divided by 2 minutes. If you do it by minutes, then it is 50.

Average speed is like your average in math class. They both take something, then add it up and divide by something.

Instantaneous Speed

Instantaneous speed is the speed at a specific moment or given time.
An example is when you say, "At 2:50 p.m., I was going 45 miles per hour."

Instantaneous speed is on the exact moment like we get out of school at exactly 3:00 p.m. The comparison is that we get out of school at a given time like the speed at a given time.