Measurement

How are SI units defined?

The relative density of lead is$11.3$. Its density is _____ $\mathrm{g} {\mathrm{cm}}^{-3}$ or $11.3 \times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$.

A vehicle moving with a speed of $18\mathrm{km} {\mathrm{h}}^{-1}$ covers _____ $\mathrm{m}$ in $1\sec$.

Number of fundamental units are present in the SI system of units are _____.

Find out six words related to measurement in the given grid. The names may read forward, backward or across.

Complete the following web chart.

Why was there a need to have a standard unit for measuring length?

The quantity which can be measured is known as a physical quantity. They have a numerical magnitude and a unit.

A piece of wire $108 \mathrm{cm}$ long is bent in the form of an isosceles triangle. If the ratio of one of the equal sides to the base is $7:3,$ then what is the length of the base?

If the area of a circle is equal to the area of square with side $4\sqrt{\mathrm{\pi }} \mathrm{units},$ then what is the diameter of the circle?

Select the unit of velocity.

Select the unit which is not a standardized unit.

Having all units in atomic standards is more useful. Explain.

$1$ light year is equal to

Light year is the unit of

The distance of a galaxy from the earth is of the order of ${10}^{25} \mathrm{m}$. The time taken by light to reach the earth from the galaxy is