In the context of scalars and vectors, how is speed different from velocity?

• A. Speed is a scalar that describes how fast an object moves, while velocity is a vector that includes both speed and direction.
• B. Speed is the rate of change of acceleration, while velocity is the rate of change of position.
• C. Speed includes direction, while velocity describes only how fast an object moves.
• D. Speed and velocity are both vectors because they both require a direction to be defined.

Answer: (A)

Verified step by step guidance

1. Understand the definitions of scalar and vector quantities: Scalars have only magnitude (size), while vectors have both magnitude and direction.
2. Recall that speed is defined as the rate at which an object covers distance, which means it only has magnitude and no direction, making it a scalar quantity.
3. Recall that velocity is defined as the rate of change of an object's position with respect to time, which includes both how fast the object is moving and the direction of its motion, making it a vector quantity.
4. Compare the two: speed tells you how fast an object is moving regardless of direction, while velocity tells you how fast and in which direction the object is moving.
5. Conclude that speed is a scalar quantity describing only magnitude, whereas velocity is a vector quantity describing both magnitude and direction.