When did metric start to be taught in British schools?

[nlogax]

Can’t say I’ve noticed it personally, although despite the stereotype of Americans having little knowledge of world outside the USA, on my visits there speaking with locals about the weather almost everyone when discussing the temperature seems almost embarrassed talking in Fahrenheit to me as a British person because I think they know it’s gibberish to the rest of the world.

Not the same experience with my east coast US friends. They have openly admit to being hugely embarrassed about their country for all manner of glaringly obvious reasons right now but they're not at all fazed about using Fahrenheit. Why would they be?

 

[najaB]

Conjecture: I suppose you could have miles per hour per minute (?) with speed of a vehicle measured in miles per hour, but acceleration measured over a smaller period of time as acceleration (even average acceleration) is unlikely to make sense over a long time period.

To be consistent (well, as consistent as Imperial measurements ever are) it would have to be miles per hour per hour or miles per second per second. The multiple of sixty in miles per hour per minute is just asking for trouble!

 

[Ediswan]

Conjecture: I suppose you could have miles per hour per minute (?) with speed of a vehicle measured in miles per hour, but acceleration measured over a smaller period of time as acceleration (even average acceleration) is unlikely to make sense over a long time period.

We already almost do. Vehicle performance/acceleration figures of 0-60 miles per hour are quoted in seconds.

(Metric does the same, for 0-100 km per hour.)

 

[Typhoon]

We already almost do. Vehicle performance/acceleration figures of 0-60 miles per hour are quoted in seconds.

(Metric does the same, for 0-100 km per hour.)

Good point. I hadn't thought about that.

 

[DelW]

Commenced secondary school in 1966 age 11 years, SI metric was fully established, in physics g = 9.8 metres/ second squared for acceleration due to gravity, never had to deal with such things as poundals

A disadvantage of metric! I would have been studying for GCSEs in '66. It was definitely 32 feet per second squared, a much easier number to do the sums with.

In many real-world engineering applications, approximating g to 10m/s^2 is sufficiently accurate, and that's easier to multiply by than 32.
Thus, for instance, something with a mass of 1 tonne will be taken as applying a gravitational force of 10 kiloNewtons.
The approximation is normally slightly on the cautious side, and in many cases other input values are only estimated anyway.

 

[Typhoon]

In many real-world engineering applications, approximating g to 10m/s^2 is sufficiently accurate, and that's easier to multiply by than 32.
Thus, for instance, something with a mass of 1 tonne will be taken as applying a gravitational force of 10 kiloNewtons.
The approximation is normally slightly on the cautious side, and in many cases other input values are only estimated anyway.

It may be but we weren't in the real world, we were in the world of exam boards. When I started teaching it was 9.8m/sec squared. It said so on the exam paper! Newton's equations of motion, v = u + at and all that No calculators at the time. Question - 'find the time taken for an object of negligible weight to fall a distance of 300 feet from rest'. Easy, lots of cancelling by 2.
Once 9.8 came along distances suddenly became a multiple of 49 and you had the decimal point to contend with so you might get it falls 2205 metres. Nightmare.

 

[DelW]

It may be but we weren't in the real world, we were in the world of exam boards. When I started teaching it was 9.8m/sec squared. It said so on the exam paper! Newton's equations of motion, v = u + at and all that No calculators at the time. Question - 'find the time taken for an object of negligible weight to fall a distance of 300 feet from rest'. Easy, lots of cancelling by 2.
Once 9.8 came along distances suddenly became a multiple of 49 and you had the decimal point to contend with so you might get it falls 2205 metres. Nightmare.

Ah, fair enough, not wise to argue with exam boards! Though at least 9.8 gives some chance of mental arithmetic, it would have been even worse if they'd insisted on 9.81 or 9.806. Were you allowed to use slide rules?

 

[Ediswan]

Question - 'find the time taken for an object of negligible weight to fall a distance of 300 feet from rest'.

Weird question. The dictionary meaning of 'negligible' is along the lines of 'not worth considering', so weightless, hence will not fall, hence the question has no answer.

 

[DelW]

Weird question. The dictionary meaning of 'negligible' is along the lines of 'not worth considering', so weightless, hence will not fall, hence the question has no answer.

Such questions also usually ignore air resistance, which can have quite a big effect on the real-world answer.

 

[najaB]

Weird question. The dictionary meaning of 'negligible' is along the lines of 'not worth considering', so weightless, hence will not fall, hence the question has no answer.

I'm also not sure why it's even necessary to specify the weight since, absent air resistance, all objects with mass will fall at the same rate.

Such questions also usually ignore air resistance, which can have quite a big effect on the real-world answer.

Which is why they usually consider spherical cows.

 

[eMeS]

....

Which is why they usually consider spherical cows.

Well, that's a new one on me, and I do have a physics degree - but, it's from 1962 !

 

[Typhoon]

Ah, fair enough, not wise to argue with exam boards! Though at least 9.8 gives some chance of mental arithmetic, it would have been even worse if they'd insisted on 9.81 or 9.806. Were you allowed to use slide rules?

No slide rules. The school possessed a few but they were a lethal weapon in some hands (protective goggles advised). If I remember rightly. questions had 'nice' answers (ones that in the right hands did not involve logs - I , that is why they were contrived.

Edit:

Such questions also usually ignore air resistance, which can have quite a big effect on the real-world answer.

Yes, you are right, I should have mentioned that (it's half a century ago) otherwise someone will use the example of a feather or similar and write a clever answer.

Basically the question means 'can you remember the formula s = ut + 1/2 a t squared. bung in the numbers in the right places and do the arithmetic - and get the units right?' In my case the answer would be 'yes', and I got an 'O' level in Physics and 'A' level in Applied Mathematics on the strength of it. Did it help me understand Physics? Not a bit of it.

I believe the estimation of '10' was allowed later, once they found out that candidates struggled with 9.8. I reckon the decimal point was the killer.

 

[eMeS]

No slide rules. The school possessed a few but they were a lethal weapon in some hands (protective goggles advised).

I remember buying my own, a low cost 5" Unique if my memory is good, and then I managed to get a 10" better quality model, and I think I've still got it. A neighbour with his own rear-garden mechanical workshop had one of the cylindrical types, where the scale was much longer, and higher accuracy was possible.