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Q: A: ### Quick Answer

**There are 86,400 seconds in a day.** This calculation is based on the conventional definition of the length of a day; for convenience, a day is defined as 24 hours.

A day is considered to be the amount of time it takes the earth to rotate once around its axis. This rotation takes 23 hours, 56 minutes and 4.1 seconds, which is exactly 86,164.1 seconds long.

If you measure the length of a day in solar time, it varies depending on the time of the year. Using solar time, the length of a day in seconds varies from 86,325 seconds to 86,471 seconds.

Learn more about MeasurementsSources:

- Q:
## How many inches is 18mm?

A:Eighteen millimeters is equal to approximately 0.70866 inches. Each millimeter is equal to 0.039370 inches. To convert between millimeters to inches, simply multiply the value in millimeters by 0.039370 to obtain the value in inches.

Full Answer >Filed Under: - Q:
## 100 grams equals how many cups?

A:Although one can convert 100 grams to cups, the conversion factor or equivalent is different, depending on the specific ingredient. Grams and cups also are two different types of measurements.

Full Answer >Filed Under: - Q:
## How many miles is a 50k?

A:

Full Answer >**50 kilometers is the equivalent of 31.07 miles.**There are 1.61 kilometers in one mile. Kilometers are used in most of the world as the standard unit of measurement for running races and traveling, but in the United States, miles are used instead of kilometers.Filed Under: - Q:
## How many cm are in a mm?

A:

Full Answer >**There is one-tenth of a centimeter in a millimeter.**Centimeters are one one-hundredth of a meter and millimeters are one one-thousandth of a meter; therefore, there are 10 millimeters for every centimeter.Filed Under: