2. Explain why it is so much safer to hit your airbag than to hit your steering wheel, dashboard, windshield, etc...

Airbags help your body stop more slowly, reducing the risk of injury and death. [Chart based on a vehicle of total mass 1500kg.] ... So even if your body is fastened tight, the same basic law of physics says your head will keep on going and smash into the steering wheel or the glass windshield (windscreen).