Kinematic Concepts - Mission KC4 Detailed Help

Which one of the following statements is true?


 
Definition of Speed:
The speed of a moving object refers to how fast the object is moving. It is the distance traveled per unit of time.
 
Definition of Velocity:
The velocity of a moving object is the rate at which the object changes its position.


 
Speed is a scalar quantity that is fully expressed by magnitude alone. Velocity is a vector quantity that is expressed by both magnitude and direction. Suppose that you are driving your car at 55 mi/hr along a road while heading east. At that instant, the speed of your car is 55 mi/hr. The velocity of your car is 55 mi/hr, east. The velocity is expressed with a magnitude (55 mi/hr) and a direction (east). In this sense, the velocity is simply the speed value with a direction.