question 18 of 25 which of the following is an expression of speed? a. 90 km b. 55 mi north c. 90 km/h north…

question 18 of 25 which of the following is an expression of speed? a. 90 km b. 55 mi north c. 90 km/h north d. 55 mph
Answer
Brief Explanations:
Speed is a scalar with magnitude and time units, no direction. Velocity includes direction. Options A (distance), B/C (with direction, velocity) are incorrect. D has magnitude and time units, no direction.
Answer:
D. 55 mph