- Home
- Standard 11
- Physics
A satellite of mass m is at a distance of $'a'$ from a star of mass $M.$ The speed of the satellite is $u.$ Suppose the law of universal gravity is $F=-G\frac{Mm}{r^{2.1}}$ instead of $F=-G\frac{Mm}{r^{2}}$ find the speed of the satellite when it is at $a$ distance $b$ from the star.
$\sqrt{u^2+2GM(\frac{1}{b^{1.1}}-\frac{1}{a^{1.1}})}$
$\sqrt{u^2+\frac{2}{1.1}GM(\frac{1}{b^{1.1}}-\frac{1}{a^{1.1}})}$
$\sqrt{u^2+\frac{2}{2.1}GM(\frac{1}{b^{1.1}}-\frac{1}{a^{1.1}})}$
$\sqrt{u^2+\frac{2}{1.1}GM(\frac{1}{b}-\frac{1}{a})}$
Solution
$\Sigma \mathrm{W}_{\mathrm{F}}=\Delta \mathrm{K}(\mathrm{WET})$
$\int_{a}^{b} \frac{-G M}{r^{2-1}} d r=\frac{1}{2} m v^{2}-\frac{1}{2} m u^{2}$
$\frac{\mathrm{GM}}{1.1}\left[\frac{1}{\mathrm{a}^{1.1}}-\frac{1}{\mathrm{b}^{1.1}}\right]=\frac{1}{2} \mathrm{mv}^{2}-\frac{1}{2} \mathrm{mu}^{2}$