Question

why is understanding quantities and units
important

Answer 1

Quantities and units are important in performing the correct calculation for an experiment and determining proper results.

Quantities: We need to have prior knowledge of type of quantities. For ex - adding 1 kg mass and 1m length doesn't make any sense, since they both are totally different quantities, the addition of these quantities will neither be 2 kg mass nor be 2 kg length. Hence we must be cleared what needs to be added and what cannot be added.

7 fundamental quantities are:

length (metre)

mass (kilogram)

time (second)

electric current (ampere)

thermodynamic temperature (kelvin)

amount of substance (mole)

luminous intensity (candela)

Units: The units need to be converted into single unit in order to perform addition/calculation. For ex - 1 L and 400 mL cannot be added directly, we first need to convert 1L = 1000 mL

and then add, 1000 mL + 400 mL = 1400 mL or 1.4L

Hence we need to make sure that all the expressions are having same units before performing any operation