Explain the difference between speed and velocity.

Speed and velocity are both measures of motion, but they have distinct differences:

Speed

• Definition: Speed is a scalar quantity that refers to how fast an object is moving. It is the rate at which an object covers distance.
• Characteristics:
  • It has magnitude only.
  • It is always positive or zero.
  • It does not indicate direction.
• Formula: Speed is calculated as the total distance traveled divided by the total time taken. $\text{Speed} = \frac{\text{Distance}}{\text{Time}}$

Velocity

• Definition: Velocity is a vector quantity that refers to the rate at which an object changes its position. It includes both speed and direction.
• Characteristics:
  • It has both magnitude and direction.
  • It can be positive, negative, or zero, depending on the direction.
• Formula: Velocity is calculated as the displacement (change in position) divided by the time taken. $\text{Velocity} = \frac{\text{Displacement}}{\text{Time}}$

Key Difference

• Direction: Speed does not consider direction, while velocity does.
• Type of Quantity: Speed is scalar, whereas velocity is vector.

Final Answer

Speed is a scalar quantity indicating how fast an object moves, while velocity is a vector quantity that describes how fast and in what direction the object moves.