Question

pre-class quiz: v-t graphs & displacement
1 multiple choice 1 point
what is the key difference between a velocity vs time (v-t) graph and a position vs time (x-t) graph?
only a v-t graph can show direction of motion.
a v-t graph shows position; an x-t graph shows velocity.
a v-t graph shows how velocity changes with time; an x-t graph shows how position changes with time.
both graphs show the same information in the same way.

Explanation:

• The first option is incorrect because an x-t graph can also show direction of motion via positive/negative position values or slope sign.
• The second option reverses the definitions of the two graphs.
• The fourth option is wrong because the graphs display different kinematic quantities (velocity vs. position) over time, so they do not show the same information.
• The third option correctly states the core purpose of each graph: a velocity-time graph tracks velocity changes over time, while a position-time graph tracks position changes over time.

Answer:

C. A v-t graph shows how velocity changes with time; an x-t graph shows how position changes with time.