Momentum Theory

[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]

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 ([math]P = M \overrightarrow{V}[/math]). 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