Answer:
C. Speed is the distance per unit of time. Velocity is the displacement per unit of time.
This answer accurately describes the difference between speed and velocity.
Step-by-step explanation:
A. If speed is constant, then velocity is also constant.
The above statement is not correct, the correct statement is if speed is constant its velocity is not necessarily constant.
Example: An object in uniform circular motion has constant speed but its velocity changes at every instant due to change in direction.
B. Speed requires direction. The direction doesn't matter when calculating velocity.
The above statement is not correct, the correct statement is
Speed does not require direction. The direction is necessary for calculating velocity.
Speed, a scalar quantity, requires magnitude only not the direction.
Velocity is vector quantity, requires magnitude as well as direction.
C. Speed is the distance per unit of time. Velocity is the displacement per unit of time.
The above statement is correct i.e.
Speed is the distance per unit of time. Velocity is the displacement per unit of time.