Units of time - century, year, month, week, day, hour, minute, second.
The units that are Obtained by combining other units is called Derived Units.
incompatible units one is measure of time the other of length.
You can't convert that. You can only convert units that measure the same type of thing - for example, units of length to units of length, units of mass to units of mass, units of time to units of time, etc.
It doesn't make sense to convert that. You can only convert units of the same kind, e.g., units of length to units of length; units of area to units of area; units of time to units of time, etc.
Density
That depends on what you are talking about. If you are talking about units of time, then it could be hours, though it could be other units of time. You could also be talking about units of some other kind entirely, that have nothing to do with time.
If this is a speed problem, use the formula: distance = speed x time. Other than that, you can't convert from units of distance to units of time.
Because nearly every other unit can be derived from them. For example, velocity is length per time (or * time^-1), and volume is length cubed
The units that are Obtained by combining other units is called Derived Units.
In the SI, it is DEFINED as a base unit, together with the unit of length, the unit of time, and a few others. Other units are derived from these base units.
It, as with many other units of measure, is a standard to which everyone can agree.
In the International System of Units (SI Units), time is measured in seconds.
incompatible units one is measure of time the other of length.
In SI, acceleration is measured in meters / second2, or meters / second / second. In other units, units of the same dimension have to be used, i.e., [length] / [time] / [time]. For example, in the imperial units, feet per square second is quite common.
The SI unit is meters/second2. You can alternately use any other units of (length) / (time) / (time).
The SI unit of time is the second. Other units of time that are often used are minute, hour, day, week, month, year, century, millenium, as well as decimal fractions of a second such as the millisecond, microsecond, or nanosecond.
The units are incompatible. One is a linear measurement the other is a period of time