Impact Force When Driving Without a Seatbelt

▣ Impact Force Without a Seatbelt

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▣ Principle of Calculation

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If we set the two energies equal, the mass m cancels out.

Here, v is velocity (m/s), and g = 9.81 m/s².

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Unit conversion for speed:

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Speed Converted to Equivalent Height (assuming one floor = 3.0 m)

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▣ Seatbelts and “Impact”

While energy (equivalent height/floors) depends on speed, the real factor that determines injury risk is the deceleration distance.

• Without a seatbelt: The body collides with the dashboard or windshield and stops within just a few centimeters → extremely high impact force.

• With a seatbelt: The belt stretches, the pretensioner activates, and the airbag deploys, increasing the deceleration distance to several tens of centimeters → dramatically reducing the impact force.

In short, even at the same speed, wearing a seatbelt drastically lowers the maximum impact your body experiences.

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▣ Proper Way to Wear a Seatbelt

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