2009 GMC Acadia Owner's Manual - Page 20
2009 GMC Acadia Manual
Page 20 highlights
1-16 Seats and Restraint System Why Safety Belts Work When you ride in or on anything, you go as fast as it goes. Put someone on it. Get it up to speed. Then stop the vehicle. The rider does not stop. Take the simplest vehicle. Suppose it is just a seat on wheels.