because it is

***per***second - the inverse, ie

10m --------------- second * second

1/x == x^-1 in this notation.

Compare, for instance, measuring carpet, which is in meters^2, ie 'square meters', meters * meters, and not a minus in sight.

HTH J^n

because it is

10m --------------- second * second

1/x == x^-1 in this notation.

Compare, for instance, measuring carpet, which is in meters^2, ie 'square meters', meters * meters, and not a minus in sight.

HTH J^n

it's metres ;-)

On Wed, 11 Sep 2019 13:06:10 -0700 (PDT), David Paste

'per second per second' is not 'seconds squared', it's 'per second squared' (perhaps you meant that but omitted the 'per').

'one tenth' or 1/10 can be written 10^-1. Metres per second per second can be written m/sec/sec or m/sec^2 or m.s^-2, the -ve sign indicating 'per' or 'one over' or division.

'per second per second' is not 'seconds squared', it's 'per second squared' (perhaps you meant that but omitted the 'per').

'one tenth' or 1/10 can be written 10^-1. Metres per second per second can be written m/sec/sec or m/sec^2 or m.s^-2, the -ve sign indicating 'per' or 'one over' or division.

--

Chris

Chris

On Wed, 11 Sep 2019 13:06:10 -0700, David Paste wrote:

It's because it's* /per/ *second, indicating dividing. ms^2 would be metre-
second-seconds (i.e. distance times time times time), while acceleration
is ms^-2, metres per second per second, distance divided by time divided
by time.
Positive powers are multiplication, negative powers are division (or
"anti-multiplication"). x^2 is x*x, x^-2 is (1/x)/x. 2^2 is 4, 2^-2 is
0.25.

If you multiply acceleration (ms^-2) by time (s, or s^1), you add the powers - and get speed in ms^(-2+1) or ms^-1. If you divide acceleration by time, you subtract the powers - and get jerk in ms^(-2-1) or ms^-3. The same applies starting with distance, in m, or ms^0. Anything to the power zero is 1, so m and ms^0 are the same thing. Divide by time and you get ms^(0-1), ms^-1.

Mike

It's because it's

If you multiply acceleration (ms^-2) by time (s, or s^1), you add the powers - and get speed in ms^(-2+1) or ms^-1. If you divide acceleration by time, you subtract the powers - and get jerk in ms^(-2-1) or ms^-3. The same applies starting with distance, in m, or ms^0. Anything to the power zero is 1, so m and ms^0 are the same thing. Divide by time and you get ms^(0-1), ms^-1.

Mike

On 11/09/2019 21:06, David Paste wrote:

Its a bit like the way you can do a division by multiplying by the reciprocal of the devisor...

So m/s^2, can become ms^-2, so its including the "per" (i.e. the division operation) into the exponent.

Its a bit like the way you can do a division by multiplying by the reciprocal of the devisor...

So m/s^2, can become ms^-2, so its including the "per" (i.e. the division operation) into the exponent.

--

Cheers,

John.

Cheers,

John.

Click to see the full signature.

While all (or perhaps most) of the answers posted are correct, I don’t think any quite get to the basic reason.

For that you need to look at the laws of indices.

4 = 2^2 2= 2^1 1 = 2^0 1/2 = 2 ^ -1 1/4 = 2^ -2 = 1/(2^2)

I’ve use 2 for simplicity but the rules apply for other numbers.

Hopefully you can see the pattern.

If we substitute m for 2 then, in particular in the last line we get:

m^-2 = 1/(m^2) which is also 1/m * 1/m

The laws of indices ‘pop up’ in a number of places and can be very useful. They are the basis of Logarithms, can be used to find HCF and LCMs, .......

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