Question

A graph titled Position versus time for 2 cars with horizontal axis time (seconds) and vertical axis position (meters). An orange line labeled A has a sharp upward slope. A blue line B has a slight downward slope.
Which statements best describe the motion of Car A and Car B? Check all that apply.

Car A and Car B are both moving toward the origin.
Car A and Car B are moving in opposite directions.
Car A is moving faster than Car B.
Car A and Car B started at the same location.
Car A and Car B pass each other at the crossover point on the graph.

Answer 1

Select:
- Car A and Car B are moving in opposite directions.
- Car A is moving faster than Car B.
- Car A and Car B pass each other at the crossover point on the graph.

Why:
- On a position vs. time graph the slope = velocity. A has a positive (upward) slope and B a negative (downward) slope → velocities opposite → they move in opposite directions.
- A’s slope is much steeper (larger magnitude) than B’s → A has the larger speed.
- Where the two lines cross they have the same position at the same time → they meet/pass there.

Not selected:
- “Both moving toward the origin” cannot be determined from slopes alone (whether a given velocity is toward the origin depends on each car’s position relative to the origin).
- “Started at the same location” is only true if their positions at t = 0 are equal; that is not given/shown.