Which of the following is a scalar quantity?

Scalar quantities are defined solely by their magnitude (a numerical value) and lack any direction. Speed, which describes how fast an object is moving, fits this definition perfectly. In contrast, velocity, displacement, and force are vector quantities. Velocity incorporates both speed and direction (e.g., 60 mph north). Displacement refers to the overall change in position, including direction (e.g., 10 meters east). Force also has direction, indicating the push or pull exerted on an object (e.g., 5 Newtons downward).