Question

airbags are supplemental protection in cars designed to work best in combination with seat belts. how do these devices protect the driver and passengers? view available hint(s) the seatbelt will keep you inside the car in case the door is open. they keep the driver and passenger in place. the bag is a softer surface to impact. with these devices, momentum is changed over a longer period of time, with a correspondingly smaller force.

Explanation:

To determine how airbags (and seat belts) protect, we use the concept of impulse (\(J = F\Delta t=\Delta p\), where \(J\) is impulse, \(F\) is force, \(\Delta t\) is time, and \(\Delta p\) is change in momentum). Airbags increase \(\Delta t\) during impact. Since \(\Delta p\) is fixed (from initial to final momentum in a crash), a larger \(\Delta t\) means a smaller \(F\) (from \(F=\frac{\Delta p}{\Delta t}\)).

• The first option is incorrect (seat belts/airbags aren’t for door - open scenarios).
• The second option is partially true (they do keep people in place, but it’s not the main physics - based protection mechanism).
• The third option is a surface - level description; the key is the time over which momentum changes.
• The fourth option correctly explains using the impulse - momentum theorem: by increasing the time of momentum change, the force is reduced.

Answer:

D. With these devices, momentum is changed over a longer period of time, with a correspondingly smaller force.