The order of magnitude of the speed of light in $SI$ units is ........

What is the number of significant digits for a number that does not represent a measurement?

Find the value of $\frac{1.53 \times 0.9995}{1.592}$ with due regard for significant figures.

An object of mass $m = 3.513 \ kg$ moves along the $x$-axis with a velocity of $5.00 \ ms^{-1}$. The magnitude of its momentum can be recorded as $...... \ kg \ ms^{-1}$.

The mass of a box measured by a grocer's balance is $2.30 \ kg$. Two gold pieces of masses $20.15 \ g$ and $20.17 \ g$ are added to the box. What is
$(a)$ the total mass of the box,
$(b)$ the difference in the masses of the pieces to correct significant figures?

Calculate the length of the arc of a circle of radius $31.0 \, cm$ which subtends an angle of $\frac{\pi}{6}$ at the centre.