Final answer:
The average speed of an object is a measure of the total distance traveled divided by the elapsed time and does not account for changes in velocity or direction. Instantaneous speed can vary at different points along the path, reflecting actual changes in motion at specific times. Average velocity, which includes direction, can be zero if the displacement is zero, despite a non-zero average speed.
Step-by-step explanation:
The average speed of an object is the total distance traveled divided by the elapsed time, and is a scalar quantity, meaning it does not have direction. However, instantaneous speed is the speed of an object at a specific point in time and can vary along the object's path due to changes in velocity or direction. For instance, if a person is driving to a store and returns home, taking 30 minutes in total and the odometer shows 6 km traveled, the average speed is 12 km/h. Nevertheless, the average velocity, which is displacement divided by time, for this round trip is zero because the starting and ending points are the same, resulting in no displacement.
Therefore, average speed can differ from instantaneous speed, as average speed does not reflect the variations in speed and direction that can happen during travel. An object might momentarily stop or change direction, affecting its instantaneous speed but not necessarily its average speed over the entire trip.
Another aspect to consider is the magnitude of average velocity, which is displacement over time and can be drastically different from average speed if the path includes changes in direction. Despite this, the instantaneous speed can still be calculated from the magnitude of the instantaneous velocity at any given point, regardless of the direction, as speed is a scalar quantity.