Position-time and velocity-time graphs

Answer Key - Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   A cart rolls forward at 4 m/s for 5 s, then backward at 2 m/s for 3 s. Ari counts forward as positive. What is its displacement from the start?

   14 m
2. 2.

   A cart rolls forward at 7 m/s for 3 s, then backward at 5 m/s for 4 s. Bo counts forward as positive. What is its displacement from the start?

   1 m
3. 3.

   A cart rolls forward at 6 m/s for 2 s, then backward at 1.5 m/s for 8 s. Esme counts forward as positive. What is its displacement from the start?

   0 m
4. 4.

   Jun reads the position-time graph. Which description of the cart's velocity matches it?

   • 6 m/s for 2 s, then 0 for 2 s, then −6 m/s for 2 s
   • 0 for 2 s, then 3 m/s for 2 s, then 0 for 2 s
   • 3 m/s for 2 s, then 0 for 2 s, then 3 m/s for 2 s
   • 3 m/s for 2 s, then 0 for 2 s, then −3 m/s for 2 s
6. 5.

   Milo reads the velocity-time graph. What is the cart's acceleration from 0 s to 6 s?

   • +2 m/s², because the cart speeds up backward
   • 0 m/s², because the cart stops at 3 s
   • −2 m/s², the same all the way
   • −6 m/s², the final velocity
7. 6.

   Noah reads the velocity-time graph. When does the cart turn around?

   Use the picture in question 5.

   • At 3 s, where the velocity changes sign
   • At 0 s, where the line starts
   • At 6 s, where the line ends
   • It does not turn, since the acceleration stays the same
8. 7.

   Pia reads the velocity-time graph. What is the cart's displacement from 0 s to 6 s?

   Use the picture in question 5.

   • 18 m: 9 m + 9 m
   • −9 m: the area of the second triangle
   • 9 m: the area of the first triangle
   • 0 m: 9 m forward, then 9 m back
9. 8.

   Ren reads the acceleration-time graph. What does the area under the line give, and how much is it?

   • 12 m: the displacement
   • 3 m/s²: the height of the line
   • 12 m/s²: the average acceleration
   • 12 m/s: the change in velocity
10. 9.

    Tala reads the velocity-time graph. What does the line say about the cart?

    • It is at rest, because a flat line means no motion
    • It slows down toward zero by 4 m/s each second
    • It speeds up backward by another 4 m/s each second
    • It moves backward at a steady 4 m/s and ends 12 m back
11. 10.

    Zee reads the position-time graph of two carts. Which statement is right?

    • Cart A is faster: 2 m/s against 1 m/s
    • Cart A is faster by 4 m/s, the gap in final position
    • Cart B is faster, because its line is lower
    • They have the same velocity, since both start at 0