$A$ cuboidal block has dimensions $(1.5 \times 1.5 \times 1.0) \ cm$. What is the total surface area of the cuboid (in $cm^2$)?

The Sun's angular diameter is measured to be $1920^{\prime \prime}$. The distance $D$ of the Sun from the Earth is $1.496 \times 10^{11} \ m$. What is the diameter of the Sun?

Accuracy of measurement of a physical quantity depends on which factors?

Given below are densities of some solids and liquids. Give rough estimates of the size of their atoms.

Substance	Atomic Mass $(u)$	Density $(10^3\,kg\,m^{-3})$
Carbon (diamond)	$12.01$	$2.22$
Gold	$197.00$	$19.32$
Nitrogen (liquid)	$14.01$	$1.00$
Lithium	$6.94$	$0.53$
Fluorine (liquid)	$19.00$	$1.14$

Explain how time was measured in ancient times. Also,write a note on the cesium clock (atomic clock).

What is the uncertainty in time measured by a cesium atomic clock?