converting mm/ms to km/h

how do you convert

419mm/900ms to km/h

i have no idea and i need help!

thanks.

[JohnS]

Originally Posted by Unregistered

how do you convert

419mm/900ms to km/h

i have no idea and i need help!

thanks.

There are 10^6 mm in 1 km and 3600 x 1000 ms in 1 hr, so
419 mm/900 ms x 1km/10^6 mm x 3.6x10^6 ms/h =
1.676 km/h.

so how do you do it if it's km/h to mm/ms? is it the similar?

[JohnS]

Originally Posted by Unregistered

so how do you do it if it's km/h to mm/ms? is it the similar?

Yes, but you will have to invert the two conversion factors above so the unwanted units cancel out.

In general, compound conversions are easily handled by cascading the two separate conversions, km to mm, and hour to second, in a "chain rule" and multiplying out.

What is 1km/h to m/s or 1m/s to km/h

[JohnS]

Originally Posted by Unregistered

What is 1km/h to m/s or 1m/s to km/h

1 m/s x 3600 s/1 h x 1 km/1000 m = 3.6 km/h

Hi,
My problem is reverse : how do I get 320 km/h to mm/ms ?

I have ESBUnitConv, but they do not list milliseconds.

Thanks a lot.

[JohnS]

Originally Posted by schnauzer

Hi,
My problem is reverse : how do I get 320 km/h to mm/ms ?

I have ESBUnitConv, but they do not list milliseconds.

Thanks a lot.

Convert to meters per second; recognize that mm/ms is the same numeric value because the two milli- prefixes cancel out.

Recognize that an hour is 3.6 ks (3600 s)
320 km/h x 1 h/3.6 ks = 88.9 m/s = 88.9 mm/ms

You get an endless repeating decimal, but you have to ask what is the practical accuracy of the 320 km/h datapoint and decide where to cut it off to avoid "decimal dust."