Question

1. During a total solar eclipse the moon almost entirely covers thesphere of the sun. Write the relation between the distances andsizes of the sun and moon.2. If the unit of force is 100 N, unit of length is 10 m and unit of time

is 100 s, what is the unit of mass in this system of units?

Answer 1

1.
The ratio of distances of the sun and moon from the earth:

$$\begin{gathered} \frac{Dis\tan c{e}_{sun}}{Distac{e}_{moon}}=\frac{149000000}{\mathrm{384,400}}=387.61 \\ \frac{Diamete{r}_{sun}}{Diamete{r}_{moon}}=\frac{\mathrm{1,392,000}}{\mathrm{3,476}}=400.46 \\ Theratiosarenearlyequalthatisthereasonwhymoonappearstocompletly \\ blockthesunduringatotalsoalreclipse. \end{gathered}$$

2.

$$\begin{gathered} asweknowthat \\ N=\frac{kg\times m}{s^2} \\ nowsubstitutingthevaluesofunitsgivenandtakingthatofmasstobe\text{'}m\text{'}inthenewsystemofunits: \\ 100=\frac{m\times 10}{{100}^2} \\ m=100000kg \end{gathered}$$