Question

The maximum and minimum distance of a comet from the sun are $8\times {10}^{12}m$ and $1.6\times {10}^{12}m$. If its velocity when nearest to the sun is $60m/s$, what will be its velocity in $m/s$ when it is farthest:

• A. $12$
• B. $60$
• C. $112$
• D. $6$

Answer 1

The correct option is A $12$

REF.Image.

The diagram :-

Given

$V_a=60m/s$

$a=1.6\times {10}^{12}m$

$b=8\times {10}^{12}m$

$\because$ The force gravitational is always directed towards the sun.

$\therefore$ Angular momentum will be conserved.

$\therefore m{V}_{a}a=m{V}_{b}b$

$\Rightarrow V_b=\frac{V_{a}a}{b}$

$=\frac{60\times 1.6\times {10}^{12}}{8\times {10}^{12}}$

$V_b=12m/s$