Compare designs that reduce the force in a collision
Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.
The same toy cart is stopped by a hard bumper in 0.05 s or a soft bumper in 0.2 s. How many times bigger is the hard bumper's average force, Ari?
The same toy cart is stopped by a hard bumper in 0.02 s or a soft bumper in 0.5 s. How many times bigger is the hard bumper's average force, Bo?
The same toy cart is stopped by a hard bumper in 0.1 s or a soft bumper in 0.3 s. How many times bigger is the hard bumper's average force, Esme?
Using the bumper table, does D's 15 N fit F = Δp ÷ Δt, Jun?
- Yes: 0.4 × 6 = 15
- No: it should be 60 N
- No: it should be 2.4 N
- Yes: 6 ÷ 0.4 = 15 N
Using the bumper table, why is spring bumper B's force 120 N instead of 6 ÷ 0.1 = 60 N, Kira?
Use the picture in question 4.
- The bounce doubles Δp to 12 kg·m/s
- The table is wrong
- Springs add their own energy
- The cart is heavier with B
Using the bumper table, foam bumper A is tried on a 4 kg cart at 3 m/s with the same 0.2 s stop. Does it still meet the 50 N limit, Luz?
Use the picture in question 4.
- Yes: it drops to 15 N
- Yes: it stays 30 N
- No: the force becomes 60 N
- No: the force becomes 600 N
Milo says a stiffer bumper that stops carts faster is gentler. Agree or disagree?
- Agree: quicker stops are gentler
- Agree: bouncing back is gentler too
- Agree: the lightest bumper wins
- Disagree: a faster stop means a bigger force
Noah says a springy bumper that bounces carts back is gentler than foam. Agree or disagree?
- Disagree: a bounce makes Δp bigger
- Agree: quicker stops are gentler
- Agree: just the force matters, not the limits
- Agree: bouncing is gentler
How could Ren improve foam bumper A to lower its force while staying under 100 g?
- Replace it with wood
- Add a spring so it bounces
- Make it from a heavier, thicker block
- Use a softer foam of the same mass
How could spring bumper B be changed so it stops carts without bouncing them back, Tala?
- Paint it
- Add a damper that soaks up the push-back
- Remove the spring
- Use a stiffer spring that stores more energy

