speed

is: the magnitude of velocity. [M2.4, M4.1, P2.1, P2.2, P7.5]

is therefore: a positive quantity. [M2.4, M4.1, P2.1, P2.2, P7.5]

has as its SI unit: [M2.4, M4.1, P2.1, P2.2, P7.5]