[Tolouse]

so i looked and this was the best place i could think of putting this

sorry, i still suck at the jargon words so i will try to make this as understandable as possible

my own experience/experiment:

i have found that when i fly off the interstate and come to a red light, i know i am slow enough to stop, but it feels like my truck is still lurching forward

when i am driving through town, i can stop at a red light no problem, but there is no forward push

it actually feels like a push from a giant wind or something


my question is:

what is this momentum at point x called when you have slowed down motion, but still feel the effects of the larger momentum still there?

is it like stored kinetic energy?

[CraigD]

Originally Posted by Tolouse

what is this momentum at point x called when you have slowed down motion, but still feel the effects of the larger momentum still there?

is it like stored kinetic energy?

Momentum is simply mass times velocity (). A car, truck, or other moving body can’t “remember” having had a greater momentum.

A vehicle with a regenerative braking system would have a bit more stored energy in its battery or other energy storage device. One with underengineered brakes (such as some antiques) might have noticeable brake fade. In cold, wet weather, a dangerous condition can occur where one’s brake disks accrete a layer of ice. But I don’t think any of these effects are what Tolouse is talking about.

Occasionally, however, a full stop from a higher speed leaves an occupant with a sense of dizziness and continued motion. This isn’t due to the physics of the car, but of our motion-sensing nervous system, primarily the semicircular canals. It can be especially pronounced when your head rocks forward during braking, rebounding to an upright, against-the-headrest-position at full stop, or during hard braking with one’s head pressed at all times against the headrest. The fluid in the semicircular canal actually has a velocity (and thus momentum) somewhat independent of the rest of our body, which is how it’s able to give us a sense of motion and balance in the first place, but occasionally, it gives inaccurate, even disorienting, perceptions.

My guess is that this is what you’re experience, Tolouse.

[Tolouse]

it could be a combination of these both since i also drive a 23yr old truck. and that was what i noticed this movement in

the first thing that came to mind was that momentum just kept building up

and i couldn't figure out if it only builds up to a certain point then levels off

or just keep building