EVERYDAY SCIENCE

Detailed explanation-1: -The Si unit given for length is ‘meter’, for mass it is ‘kilogram’ and for the time it is ‘second’. Though length, mass and time can be expressed in terms of other units as well but these are the standard units used uniformly all over the world.

Detailed explanation-2: -The meter, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m s-1, where the second is defined in terms of Cs. The kilogram, symbol kg, is the SI unit of mass.

Detailed explanation-3: -The basic unit of length in the metric system is the meter. All units of length in the metric system are derived from the meter. The prefix “centi-“means one hundredth. Conversion between units of length in the metric system involves moving the decimal point to the right or to the left.

Detailed explanation-4: -As such, the correct spelling to refer a unit of measure for length is “metre.” For example, a physical distance of 1 metre (can be written also as 1 m).

Detailed explanation-5: -The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second. This definition fixed the speed of light in vacuum at exactly 299792458 metres per second (≈300000 km/s or ≈1.079 billion km/hour).