EXERCISES

The photograph of a house occupies an area of $1.75 {\mathrm{cm}}^2$ on a $35 \mathrm{mm}$ slide.  The slide is projected on to a screen, and the area of the house on the screen is $1.55 {\mathrm{m}}^2$.  What is the linear magnification of the projector-screen arrangement?

State the number of significant figures in the following:

$2.64\times {10}^{24} \mathrm{kg}$

State the number of significant figures in the following:

$0.2370 \mathrm{g} {\mathrm{cm}}^{-3}$

State the number of significant figures in the following :

$6.320 \mathrm{J}$

State the number of significant figures in the following:

$6.032 \mathrm{N} {\mathrm{m}}^{-2}$

State the number of significant figures in the following:

$0.0006032 {\mathrm{m}}^2$

The mass of a box measured by a grocer’s balance is $2.30 \mathrm{kg}$. Two gold pieces of masses $20.15 \mathrm{g}$ and $20.17 \mathrm{g}$ are added to the box. What is the difference in the masses of the pieces to correct significant figures?

The nearest star to our solar system is $4.29$ light years away. How much is this distance  in terms of parsecs? How much parallax (in arc seconds) would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun?