The statement is false as instantaneous speed can change over time. While speed is just a scalar quantity indicating magnitude, velocity is a vector and includes direction as well. A change in either speed or direction affects velocity, but a speedometer only measures instantaneous speed, not velocity.
The statement that instantaneous speed does not change because the speed hasn't increased or decreased is false. Instantaneous speed is the speed at any given moment in time, and it can change even though it has no directional component. On the other hand, instantaneous velocity includes both the magnitude and the direction of motion. Therefore, even if the magnitude (speed) does not change, a change in direction constitutes a change in velocity.
Further clarifications include that the magnitude of instantaneous velocity is equal to the instantaneous speed and is a scalar quantity, meaning it only has magnitude and no direction. However, instantaneous velocity is a vector quantity, which means it includes both magnitude and direction.
Lastly, it's important to note that a speedometer in a car does show instantaneous speed, but not instantaneous velocity because it does not indicate direction.