Compare designs that reduce the force in a collision

Answer Key - Grade 11 Science Worksheet

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

1. 1.

   A 2 kg toy cart at 3 m/s must be stopped with an average force of no more than 15 N. How long must the stop last, Ari?

   0.4 s
2. 2.

   A 0.5 kg toy cart at 6 m/s must be stopped with an average force of no more than 5 N. How long must the stop last, Esme?

   0.6 s
4. 3.

   In the bar chart, how do the two stops' changes in momentum compare, Jun?

   • The hard stop's change is bigger
   • They are the same, 6 kg·m/s
   • Neither changes momentum
   • The soft stop's is bigger
5. 4.

   In the bar chart, how many times smaller is the soft stop's force, Luz?

   Use the picture in question 3.

   • The same
   • 5 times bigger
   • 5 times smaller
   • 0.2 times smaller
7. 5.

   Using the bumper table, with force under 50 N and added mass at most 100 g, why isn't D chosen, Milo?

   • It bounces the cart back
   • Its force is too high
   • It adds 150 g, over the limit
   • It stops the cart too slowly to count
8. 6.

   Using the bumper table, a classmate picks C because it is lightest. Why does C fail, Noah?

   Use the picture in question 5.

   • It is too heavy
   • It is the right pick, being lightest
   • It bounces the cart back
   • Its 300 N force breaks the force limit
9. 7.

   Using the bumper table, a classmate picks D because its force is lowest. What should Pia point out?

   Use the picture in question 5.

   • D bounces the cart back
   • D's force is too high
   • D wins on force, so pick it
   • D breaks the 100 g mass limit
10. 8.

    Why should every bumper be tested with the same cart at the same speed, Ren?

    • So the bumpers wear out evenly
    • To raise the force
    • To make the test quicker
    • So only the bumper changes
11. 9.

    Why should each bumper be tested several times, Tala?

    • To make the cart faster
    • To lower the force
    • To check the results are reliable
    • To change the cart's mass between runs
12. 10.

    A very thin, soft foam bumper squashes completely flat in a test. What problem does that cause, Zee?

    • Nothing; flat foam works well
    • The cart stops suddenly at the end, with a big force
    • The force drops to zero
    • The cart bounces back faster