Question

Hannah made a chart to describe speed and velocity.

A 2-column table with 4 rows. The first column is labeled speed with entries scalar quantity, calculated by dividing time by distance, has magnitude, depends on a reference frame. Second column is labeled velocity with entries vector quantity, calculated by dividing change in position by time, is a displacement, depends on a reference frame.
Which best describes how to correct Hannah’s error?

Switch the chart headings “Speed” and “Velocity.”
Describe the calculation for speed as “dividing distance by time.”
In the “Speed” column, change “has magnitude” to “is a displacement.”
Change the last row of the “Velocity” column to “does not depend on a reference frame.”

Answer 1

Describe the calculation for speed as “dividing distance by time.”

Reason: Hannah reversed the ratio (she wrote time ÷ distance). Speed = distance/time. Velocity = displacement/time (and is a vector with magnitude and direction), so the other entries are not the primary error.