What two units of measurement are necessary for describing speed?

Speed is defined as the distance traveled per unit of time. To quantify speed, you must know how far an object has traveled (distance) and how long it took to travel that distance (time). The standard unit for distance in the metric system is meters, while the standard unit for time is seconds. Therefore, speed is expressed in units such as meters per second (m/s), which clearly demonstrates the relationship between distance and time.

The other options do not pertain to the direct definition of speed. Mass and force are related to dynamics and Newton's laws rather than speed. Acceleration involves a change of speed over time but does not define speed itself, and momentum is a measure of motion involving mass and velocity, not speed directly. Thus, the correct choice focuses on the fundamental components needed to calculate speed effectively: distance and time.