Thread: SI units Q

In uni I have a module on SI units and basic units, its troubling me a bit unfortunately. I am ok with them but im not very confident that the answer I get is always right which is a bit annoying.

I have one which I don’t really understand.

P=Tω P=5kW
‘n’=1440 rev min^-1(rpm)
(hence derive ‘ω’)

Find value for T in Nm.


I think the rpm needs to be in seconds but it still does not really fit in, P is power in Kilowatt. I don’t suppose I need to work 1440rpm in radians per second do I?
It just hasn’t clicked for me I’m afraid.

Also, does anyone know of some good books that cover this subject, I have Engineering Mathematics by K A Stroud but it doesn’t cover it.

Thanks a lot guys.

Originally Posted by Jonny6001

In uni I have a module on SI units and basic units, its troubling me a bit unfortunately. I am ok with them but im not very confident that the answer I get is always right which is a bit annoying.

I have one which I don’t really understand.

P=Tω P=5kW
‘n’=1440 rev min^-1(rpm)
(hence derive ‘ω’)

Find value for T in Nm.


I think the rpm needs to be in seconds but it still does not really fit in, P is power in Kilowatt. I don’t suppose I need to work 1440rpm in radians per second do I?
It just hasn’t clicked for me I’m afraid.

Also, does anyone know of some good books that cover this subject, I have Engineering Mathematics by K A Stroud but it doesn’t cover it.

Thanks a lot guys.

Yes, you need rpm in rad/s. Do you know how to convert it?

-Dan