A 2 kg test object moving at 3 m/s is brought to rest without rebound. The current design stops it in 0.02 s; a reusable foam insert stops it in 0.06 s. Consider only the contact force along the horizontal direction and use average force = momentum change / stopping time. The proposed design reduces damage to fragile school instruments, but costs more initially and requires return transport. Evaluate adoption for the school and the delivery workers, using both a force calculation and wider implications. Evidence limitation: The test used one dry temperature; wet and cold conditions may change cushioning.

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Momentum-change magnitude 6 kg m/s; average force falls from 300 N to 100 N. A conditional, tested adoption is defensible; average force alone does not establish complete safety or best value. The same test mass loses the same speed in both designs, so the impulse magnitude is 2 × 3 = 6 kg m/s. The longer stopping time changes the force, not the total required momentum change. The original average force is 6/0.02 = 300 N and the proposed force is 6/0.06 = 100 N. Both act opposite the initial motion. Relate the calculation to the specific benefit: a reusable foam insert reduces damage to fragile school instruments. The smaller average contact force is evidence for improved performance under this test, not a claim that energy or momentum disappears. Balance that benefit against a practical consequence: the design costs more initially and requires return transport. Include the needs of the school and the delivery workers, rather than allowing the cheapest purchase price or lowest force alone to decide. A justified recommendation is a monitored trial with a stated acceptance test before broad adoption. The test used one dry temperature; wet and cold conditions may change cushioning. Report peak force, durability and relevant access constraints alongside the average-force calculation.

Reusable parcel insert

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