F=ma, yesterday, today and tomorrow!

[Alphonse]

At the end of each and every day, F still equals ma.

Ole Issac had it figured out and printed it for us in 1687.

Thought I should post a reminder since there are a few here that seem to believe it is no longer valid.

[McDave]

That's all well and good, but is it momentum (mv) or kenetic energy (m*v2) that really matters? Torque or horsepower? Inquiring minds want to know!

[DanB]

Is the membership of this forum really at the level of sophomoric insults?

Can't we all just go camping.

[Protagonist]

Originally Posted by DanB

Is the membership of this forum really at the level of sophomoric insults?

Can't we all just go camping.

Considering that some people on this forum didn't study physics and don't even know what F=ma means, methinks the folks who were meant to be insulted may not realize that they have been.

Gravity: It's not just a good idea, it's the law!

[Jim & Susan]

Originally Posted by Alphonse

At the end of each and every day, F still equals ma.

Ole Issac had it figured out and printed it for us in 1687.

Thought I should post a reminder since there are a few here that seem to believe it is no longer valid.

F (force) = the amount of force it takes to open the fridge door?

M (mass) = my mass or the mass of the beer? My mass is about 180 lbs as measured in Terran units. The beer I'm not exactly.sure.

A (acceleration) = is that how much effort it takes to perform a 12oz curl, or is it measured otherwise?

He said with tounge firmly planted in cheek.

Jim

[markdoane]

Perhaps F=ma in your classical world, but in my quantum Einstein universe it doesn't always hold true.
Yesterday, today; maybe tomorrow. But not everywhere.

[Jim & Susan]

Originally Posted by markdoane

Perhaps F=ma in your classical world, but in my quantum Einstein universe it doesn't always hold true.
Yesterday, today; maybe tomorrow. But not everywhere.

True. But if quantum entanglement is real, you could be making a gnat fart itself to death in an unknown part of the observable universe just by pressing the brake pedal on yer TV.

Think about it. It could happen.

Jim

[Sbb]

Huh, just a little old shop keeper, wife and mom of five, no idea what u r talking about. Off to camp

[Jim & Susan]

Originally Posted by Sbb

Huh, just a little old shop keeper, wife and mom of five, no idea what u r talking about. Off to camp

Nor does anybody else in this thread. We're just spouting useless info we saw on the Science Channel. Have agreat weekend camping. Wish I was there with u.

Jim

[BoldAdventure]

Add to that, the minimum stopping distance for an automobile is determined by the effective coefficient of friction between the tires and the road and has nothing to do with MASS. I did the math awhile ago here: http://www.airforums.com/forums/f516...ml#post1562434

[Piggy Bank]

True but F=MA is the reason I would never want a Smartcar.

[kb0zke]

"True but F=MA is the reason I would never want a Smartcar." A Smartcar can't tow much. They are towable four down, though, so if you have a MH you can use one as a toad.

[perryg114]

All well and good till the tires slip. Once the tire is locked, the rotor size is not relevant. Frictional forces increase with weight which is W=mg. Which really is F=ma.

Perry

Originally Posted by BoldAdventure

Add to that, the minimum stopping distance for an automobile is determined by the effective coefficient of friction between the tires and the road and has nothing to do with MASS. I did the math awhile ago here: http://www.airforums.com/forums/f516...ml#post1562434

[mayco]

Well.......the F riggin rooster next door started crowing at 2:00 aM this morning and THAT = fried chicken

[mandolindave]

A guy walks into a bar. Bartender says," Awe, why the long face" ( No, he wasn't a horse ). The guy says, " I was in an accident, my car flipped"

Mandolin Dave ( 160 lbs) and some skinny guy to the rescue. The skinny guy and I, flipped the car back over…barehanded. The guy got in…..it started up, And he drove his JEEP away.

True story

[Mach5]

Let us assume we are talking about a tow vehicle's ability to dissipate the difference in potential energy of a truck/trailer combo during the descent of a downhill grade. Let us also assume that the truck is not a hybrid and does not store any energy in a battery or flywheel, and that the speed and associated kinetic energy of the truck/trailer combo (hopefully) does not increase while descending the grade. Then 100% of the potential energy difference (mass of truck/trailer combo times the difference in elevation) must be converted to heat, either through aerodynamic drag, disk and drum brake heating, or engine and transmission braking (or really long skid marks).

Given the above simplified black box model, I find it hard to believe that a light duty passenger vehicle is as capable of converting that energy to heat as a purpose built truck that is designed to do just that. I believe that heavy duty brakes, transmissions, and engines brakes have less to do with total stopping power from 60 - 0 and more to do with sustaining that braking power over prolonged periods of time, as in going down long grades.

Not preaching or advising any course of action, just my thoughts on how I would approach a seemingly difficult problem, using a simplified physical analysis, to inform my selection of an appropriate tow vehicle.

[perryg114]

Bigger stuff just means it lasts longer and takes longer to fail under extreme conditions. Bigger brakes will not heat up as fast and wear out soon or fail entirely when the fluid boils and you have NO BRAKES AT ALL.

Perry

[Gene]

Originally Posted by DanB

Is the membership of this forum really at the level of sophomoric insults?

Can't we all just go camping.

Yes we can go camping, but sophmorism is essential to the Forum. Many of we lowbrows are unable to rise above it and content to wallow in it. Silliness keeps us going. Anyway, all this physics stuff makes me remember why college physics convinced me to be a liberal arts major. But F = MA means Finance = Mergers & Acquisitions. The symbol F could be replaced by the symbol $. Now you know why I was so bad in physics, though calculus was even worse.

Gene