Momentum and impulse

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   A 0.5 kg ball hits a wall at 4 m/s and bounces straight back at 4 m/s. The contact lasts 0.05 s. What is the average force on it, Ari?

   80 N
2. 2.

   A 1.5 kg cart hits a spring bumper at 2 m/s and bounces straight back at 1 m/s. The contact lasts 0.1 s. What is the average force on it, Esme?

   45 N
4. 3.

   In the momentum bar chart, what is the ball's change in momentum, Jun?

   • −4 kg·m/s
   • +4 kg·m/s
   • −2 kg·m/s
   • 0 kg·m/s, since the speed is the same
5. 4.

   In the momentum bar chart, how fast is the ball moving before and after the bounce, Kira?

   Use the picture in question 3.

   • 1 m/s both times
   • 2 m/s both times
   • 4 m/s both times
   • 4 m/s, then 0
6. 5.

   In the momentum bar chart, the bounce lasts 0.1 s. What is the average force on the ball, Luz?

   Use the picture in question 3.

   • 0.4 N
   • 20 N
   • 40 N
   • 0 N, since the speed didn't change
7. 6.

   Milo says the heavier of two carts always has more momentum. Agree or disagree?

   • Disagree: speed matters too
   • Agree: a longer stop means a bigger force
   • Agree: direction doesn't matter, so compare masses
   • Agree: momentum is just mass
8. 7.

   Noah says a ball that bounces back at the same speed had no change in momentum. Agree or disagree?

   • Disagree: its direction flipped
   • Agree: the speed didn't change
   • Agree: momentum depends just on speed
   • Agree: a soft wall makes the force bigger
9. 8.

   Pia says a foam bumper lowers the force on a cart because it makes the stop take longer. Agree or disagree?

   • Disagree: longer stops mean bigger forces
   • Disagree: the cart's mass alone matters
   • Agree: F = Δp ÷ Δt
   • Disagree: momentum has no direction, so foam can't help
10. 9.

    Ren wants a bumper that stops carts gently. Which design helps most?

    • A springy plate that bounces carts back
    • A thinner wooden block
    • Thick foam that squashes slowly
    • A hard steel plate
11. 10.

    A springy bumper bounces carts back instead of stopping them. What happens to the impulse it gives, Tala?

    • It gets smaller
    • It becomes zero
    • It gets bigger
    • It stays the same