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?

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

   Kira reads the position-time graph. What is the cart's velocity during the first 3 s?

   • +1 m/s: the position stays positive throughout
   • −1 m/s: it moves toward the origin
   • −3 m/s: the total drop in position
   • 4 m/s: the position it starts from
6. 6.

   Luz reads the position-time graph. What is the cart's velocity?

   • −2.5 m/s: the starting position divided by the time
   • −8 m/s: the whole drop in position
   • −2 m/s: the position falls 8 m in 4 s
   • +2 m/s: the position falls, but speeds are positive
8. 7.

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

   • 0 m/s², because the cart stops at 3 s
   • −6 m/s², the final velocity
   • +2 m/s², because the cart speeds up backward
   • −2 m/s², the same all the way
9. 8.

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

   Use the picture in question 7.

   • −9 m: the area of the second triangle
   • 18 m: 9 m + 9 m
   • 0 m: 9 m forward, then 9 m back
   • 9 m: the area of the first triangle
10. 9.

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

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

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

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