The Earth is revolving around the sun on an orbit of radius 1.5×10⁸Km. If the time of one revolution is  3.156×10⁷s , what is the mass of the Sun? (G= 6.67×10¹¹ Nm²Kg^-2)

A planet of radius $R = 1/10 \times$ (radius of Earth) has the same mass density as Earth. Scientists dig a well of depth $R/5$ on it and lower a wire of the same length and of linear mass density $10^{-3} kgm^{-3}$ into it. If the wire is not touching anywhere, the force applied at the top of the wire by a person holding it in place is (take the radius of Earth $= 6 \times 10^6 m$ and the acceleration due to gravity on Earth is $10 ms^{-2}$)

নিচের কোনটি মহাকর্ষীয় ধ্রুবকের একক নির্দেশ করে?

The ratio of Earth's orbital angular momentum ;(about the sun) to its mass is $4.4 \times 10^{15}\ m^{2}\ s^{-1}$.& ;The area enclosed by the earth's orbit is approximately

কৃত্রিম উপগ্রহ পৃথিবীপৃষ্ঠ হতে পৃথিবীর ব্যাসার্ধের (R) সমান উচ্চতায় ঘুরলে এর বেগ হবে—