Yes, you’re off base.
The amount of force you experience has nothing to do with the vehicle you’re in, but the acceleration (positive or negative) you experience. In the case of a brake check, the only factors are starting speed, ending speed, distance, and time. It doesn’t matter if you’re increasing speed (positive acceleration) or slowing down (negative acceleration), the total force will be the same (just different directions).
Here are some formulas:
- acceleration = change in velocity / change in time
- force = mass * acceleration
In this case, the mass is your mass, since you’re the one experiencing the acceleration.
If you’re riding a bicycle at 15mph and slam on the brakes and stop in 10 feet, you’ll feel exactly the same force as being in a massive truck going 15mph and stop in 10 feet.
cynar@lemmy.world 3 weeks ago
The momentum matters when you hit something. A large truck has a lot more momentum than a small car. If it hits something it needs proportionally more force to stop it. Since forces are equal and opposite, that means the hit object has to absorb more force. Basically thing of the difference between someone dropping a marble on your head from a balcony to doing the same with a bowling ball. It’s the same with a child hit by a vehicle.
For passengers, only their mass matters. Whether you’re in a car, a truck, a train or an ocean liner, all that matters is the person’s mass and the rate of change.