---
title: "A robotic cart moves along a straight track in a laboratory. The position of the cart as a function of time is recorded and plotted on the graph shown.  Which of the following is a correct description of the cart’s motion?"
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url: "https://nerd-notes.com/ubq/113916/"
date_modified: "2026-06-22T07:38:21+00:00"
---

# A robotic cart moves along a straight track in a laboratory. The position of the cart as a function of time is recorded and plotted on the graph shown.

Which of the following is a correct description of the cart’s motion?

A robotic cart moves along a straight track in a laboratory. The position of the cart as a function of time is recorded and plotted on the graph shown.

Which of the following is a correct description of the cart's motion?

![A position-time graph with position x in meters on the vertical axis and time t in seconds on the horizontal axis. The t-axis has labels at 0, 2, 4, and 6 seconds. The x-axis has labels at 0, 2, 4, 6, and 8 meters. The graph consists of three distinct segments. Segment 1 from t = 0 to t = 2 is a curve that starts at (0,0) with a zero slope and curves upward (concave up) to end at the point (2, 2). Segment 2 from t = 2 to t = 4 is a perfectly straight line connecting (2, 2) to (4, 6). Segment 3 from t = 4 to t = 6 is a curve starting at (4, 6) and curving downward (concave down) until it reaches (6, 8) where the tangent to the curve is horizontal.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1782113901-qMQ6C9.jpg)

- **A.** For the interval from \( t = 0 \) to \( t = 2 \text{ s} \), the velocity of the cart is constant because the position of the cart is increasing.
- **B.** For the interval from \( t = 2 \) to \( t = 4 \text{ s} \), the acceleration of the cart is zero because the slope of the position-time graph is constant.
- **C.** For the interval from \( t = 4 \) to \( t = 6 \text{ s} \), the velocity of the cart is increasing because the cart is moving further away from the origin.
- **D.** For the interval from \( t = 4 \) to \( t = 6 \text{ s} \), the acceleration of the cart is positive because the cart is moving in the positive \( x \)-direction.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/113916/*