If the weight of a vehicle is doubled, would the deceleration of the vehicle be doubled? For example if a car decelerated at 6m/s, would a car double the size, decelerate at 12m/s or is their some other factor involved?

Question

Thanks for your help

Answer 1

How fast a car decelerates depends upon how strong a force is applied to the brakes, unless the tires skid. If that happens, the friction force is proportional to the weight, so the deceleration rate is
(Friction force/mass)
which is independent of weight. This assumes the skidding tire kinetic friction coefficient ramains the same.