SI units and the MKS system

In this course -- and in most succeeding physics courses -- we will use SI (Système International) units.

Explanation of SI units from NIST

We'll adopt the MKS units, which are based on the meter, kilogram and second. You already know what a second is, I hope, but you may be less familiar with meters and kilograms. So, let's list some familiar objects and their properties in this system. Of course, all these values are very approximate.

length

adult human = 2 m
child = 1 m
thumb = 0.05 m = 5 cm
football or soccer field = 100 m
RIT campus width = 1000 m
New York to Los Angeles = 5,000,000 m

mass

adult human = 60 kg
textbook = 2 kg
car = 1500 kg

speed

walking human = 1 m/s
running human = 10 m/s
auto on highway = 30 m/s
airplane = 250 m/s

density

water or flesh = 1000 kg/m³ = 1 g/cm³
rock = 5000 kg/m³

For more information

NIST reference pages on units