Stoopid basic physics question / just checking (rusty brain).

Lots and lots of times.

Reply to
The Natural Philosopher
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So that explains all the cases of obesity in the modern world ;-)

Reply to
whisky-dave

Two or three hundred apples.

Reply to
Davey

No, you are perfectly correct if taking their terms literally.

However it is very common for mass to be used to interchangeably with weight, that its hard to argue they are wrong as such. If someone ask how much do you weigh, you probably don't answer in Newtons.

Reply to
John Rumm

That would make BMI calculations more difficult.

Colin Bignell

Reply to
Nightjar

I'm not sure of the quantities but for Optiks it was I beams and for Natural Philosophy it was in I sacks.

Reply to
Weatherlawyer

I don't know the weight of Newton. But I do know that a newton (small 'n') is roughly the weight of an apple.

Robert

Reply to
RobertL

Yes, your weight is less on the moon, but your BMI is the same.

Robert

Reply to
RobertL

Core.

Reply to
Huge

Normally you're on the ball with most things, and yet trivial things like this trip you up. Schools drum into their pupils that weight is the force on an object due to gravity. It is measured in newton. For some who likes to measure in kg, you can use kg-wt, or if old fashioned kgf.

For people who just don't know anything about physics, then by all means use native kg to measure weight. I recall you picking on someone who used kW and energy interchangeably!! If someone neither knows or cares about time or, in this case, gravity then ignorance is bliss.

Reply to
Fredxx

If you are suspected of overloading it, you will be taken to a weighbridge where *weight* will be measured, not mass.

While it is not uncommon to see weights (incorrectly) quoted in kg, engineers would quote them in kgf, (i.e. kilograms force, or the force exerted by gravity on a mass of one kilogram).

Reply to
newshound

well then schools are wrong.

I was certainly never taught that. And my physics teacher was a Cambridge Phd nuclear physicist.

weight is common talk for mass. That's all. Not force.

Reply to
The Natural Philosopher

Why do you say that?

Exactly what you were taught at school depends critically on the exact date that you were there. Same applies to the obsessive pedantry about centrifugal (old) vs centripetal (new) pseudoforces for circular motion.

Around the mid-70's it was definitely weight = mg

Chemistry the same thing meant calling acetic acid, ethanoic acid etc.

Not quite since most people know that things are weightless when they are in orbit. The brighter ones know or have seen that you can also be weightless when in parabolic flight on Earth (eg the vomit Comet).

And in common usage most scales do measure *weight* and not mass.

The difference is largely academic since g on the Earth which is nearly spherical only varies from 9.78-9.83 from equator to pole - or about 5%.

g = pi^2 was an allowed approximation.

Reply to
Martin Brown

or more accurately, about 0.5%

Reply to
Titus Aduxass

1,600 kg x

drinking...

physics. F=ma

mass, thats

weight is

I despair. I have spent the last 32 years teaching that weight is a force. Mass is a property of an object, a measure of its inertia. Weight is a property due to where an object is in a gravitational field. Mass is measured in kg, weight is measured in N. Just because common parlance uses these terms differently, doesn't make it right.

Reply to
Lawrence

When all around you are wrong, and you're the only right person then now is the time you should start worrying.

So someone else out of touch with SI units.

I agreed that it was, common talk by people who don't know better. I genuinely thought you did.

Reply to
Fredxx

Wouldn't this imply that a mass in free fall should still have weight?

Reply to
Tim Streater

Yeah, bummer isnt it?

Reply to
The Natural Philosopher

it has - just bring it down to earth and you will find it has. :-)

Reply to
The Natural Philosopher

Obviously the concept of weight and mass are lost on you. Teaching science has come a long way since your day, albeit at the cost of literacy!!

Reply to
Fredxx

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