Four particles,each of mass $M$,move along a circle of radius $R$ under the action of their mutual gravitational attraction as shown in the figure. The speed of each particle is:

Two identical particles of mass $1 \, kg$ each go round a circle of radius $R$,under the action of their mutual gravitational attraction. The angular speed of each particle is:

Match the column $-I$ with column $-II$ for a satellite in circular orbit:

Column $-I$	Column $-II$
$(A)$ Kinetic energy	$(p)$ $-\frac{GM_Em}{2r}$
$(B)$ Potential energy	$(q)$ $\sqrt{\frac{GM_E}{r}}$
$(C)$ Total energy	$(r)$ $-\frac{GM_Em}{r}$
$(D)$ Orbital velocity	$(s)$ $\frac{GM_Em}{2r}$

(where $M_E$ is the mass of the earth,$m$ is the mass of the satellite,and $r$ is the radius of the orbit)

$A$ gas molecule of mass $M$ at the surface of the Earth has kinetic energy equivalent to $0\,^{\circ}C$. If it were to go up straight without colliding with any other molecules,how high would it rise? Assume that the height attained is much less than the radius of the Earth. ($k_B$ is Boltzmann constant)

Two particles of equal mass $m$ go round a circle of radius $R$ under the action of their mutual gravitational attraction. The speed of each particle is

$A$ person whose mass is $100\, {kg}$ travels from Earth to Mars in a spaceship. Neglect all other objects in the sky and take acceleration due to gravity on the surface of the Earth and Mars as $10\, {m/s^2}$ and $4\, {m/s^2}$ respectively. Identify from the below figures,the curve that fits best for the weight of the passenger as a function of time.