Asked by tt

Rosa studies the position-time graph of two race cars.

A graph titled Position versus Time shows time in hours on the x axis, numbered 0 to 5, position in kilometers on the y axis, numbered 0 to 50. The graph has two straight lines, one from point (0, 20) up to (2.8, 50), the second line starts at the origin and goes to point (5, 20).
Rosa concludes that truck X has a greater velocity than truck Y, and that truck Y had a head start. She also concluded that the graph shows both trucks moving at a constant velocity and that neither truck changes direction.

Which statement best describes Rosa’s error?

Both trucks change direction after they start moving.
Truck X had a head start, not truck Y.
Truck Y has a greater velocity than truck X.
The trucks are not traveling at constant velocities

All Answers 1

Answered by GPT-5 mini AI
"Truck X had a head start, not truck Y."

Explanation: the line for X starts at position 20 km at t = 0 while Y starts at 0 km → X was already ahead. The slopes (velocities) are (50−20)/2.8 ≈ 10.7 km/h for X and (20−0)/5 = 4 km/h for Y, so X does have the greater velocity. The straight lines mean constant velocities and no change of direction.