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 4 kg toy cart at 2 m/s must be stopped with an average force of no more than 10 N. How long must the stop last, Bo?

   0.8 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?

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

   In the bar chart, what are the average forces for the hard and soft stops, Kira?

   Use the picture in question 3.

   • Hard 0.3 N, soft 1.5 N
   • Hard 24 N, soft 120 N
   • Hard 120 N, soft 24 N
   • Both 6 N
6. 5.

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

   Use the picture in question 3.

   • 5 times bigger
   • 5 times smaller
   • The same
   • 0.2 times smaller
8. 6.

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

   • It adds 150 g, over the limit
   • Its force is too high
   • It bounces the cart back
   • It stops the cart too slowly to count
9. 7.

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

   Use the picture in question 6.

   • It bounces the cart back
   • It is too heavy
   • Its 300 N force breaks the force limit
   • It is the right pick, being lightest
10. 8.

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

    Use the picture in question 6.

    • D breaks the 100 g mass limit
    • D wins on force, so pick it
    • D bounces the cart back
    • D's force is too high
11. 9.

    Why should each bumper be tested several times, Tala?

    • To lower the force
    • To make the cart faster
    • 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?

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