# Question #37b98

##### 1 Answer

The FPS units of measurement are the foot, pound, and second.

#### Explanation:

The **FPS** (foot–pound–second) system is built on three fundamental units:

- foot for length
- (avoirdupois) pound for mass
- second for time.

**Foot**

The **foot** is defined as being equivalent exactly to 0.3048 m.

One foot represents a length of twelve inches, and three feet equal one yard.

**Avoirdupois Pound**

The international **avoirdupois pound** is defined as exactly 0.453 592 37 kg.

One pound is divided into sixteen ounces.

**Second**

The second is defined as the time that elapses during

There are sixty seconds in a minute, sixty minutes in an hour, and twenty-four hours in a day.

**The SI**

The corresponding SI units are the metre, kilogram, and second.

**Metre**

The metre is defined as the distance traveled by light in a vacuum

in

**Kilogram**

The **kilogram** is defined as being equal to the mass of the International Prototype Kilogram (IPK), a platinum-iridium cylinder that is kept in a high-security vault outside Paris.

1 kg = 1000 g, and 1 g = 1000 mg

**Second**

The definition of the second is the same in both the FPS system and the SI.

**The Big Differences**

**(a)** FPs is not coherent

In a **coherent** system of units, all derived units are derived by simple multiplication or division without only "1" as a proportionality factor.

For example, in the SI, the standard unit of volume is #"1 m"^3".

In the FPS system, the gallon is not equal to a cubic yard or the cube of any length unit.

**(b)** SI fractions and multiples of units are expressed as powers of 10.

1 km = 1000 m; 1 m = 1000 mm, etc.

In the FPs system, 1 mi = 1760 yd; 1 yd = 3 ft; 1 ft = 12 in.