Question

rosa studies the position - time graph of two race cars. which statement best describes rosas 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.

Explanation:

Step1: Analyze the position - time graph

In a position - time graph, the slope of the line represents velocity. A straight line indicates constant velocity.

Step2: Check for head - start

Truck Y starts at a non - zero position (20 km), so it has a head - start. Truck X starts at 0 km.

Step3: Check for direction change

Since both lines are straight (constant slope), there is no direction change.

Step4: Compare velocities

The slope of Truck Y's line is steeper than Truck X's. Slope \(m=\frac{\Delta x}{\Delta t}\). For Truck Y, if we assume at \(t = 3h\), \(x = 50km\) (approximate from the graph), \(m_Y=\frac{50 - 20}{3}=\frac{30}{3}=10km/h\). For Truck X, if at \(t = 5h\), \(x = 20km\), \(m_X=\frac{20-0}{5} = 4km/h\). So Truck Y has a greater velocity.

Answer:

Truck Y has a greater velocity than truck X.