An artificial satellite of mass $m$ is moving along an elliptical path around the Earth. The areal velocity of the satellite is proportional to

$A$ ray of light strikes a plane mirror $M$ at an angle of $45^o$ as shown in the figure. After reflection,the ray passes through a prism of refractive index $1.5$ whose apex angle is $4^o$. The total angle through which the ray is deviated is......$^o$

The $rms$ value of the electric field of light coming from the Sun is $720\, N/C$. The average total energy density of the electromagnetic wave is

The compound insoluble in acetic acid is

$A$ coin is dropped in a lift. It takes time $t_1$ to reach the floor when the lift is stationary. It takes time $t_2$ when the lift is moving down with constant acceleration $a$. Then:

$A$ beaker full of hot water is kept in a room. If it cools from $80\,^{\circ}C$ to $75\,^{\circ}C$ in $t_1$ minutes,from $75\,^{\circ}C$ to $70\,^{\circ}C$ in $t_2$ minutes,and from $70\,^{\circ}C$ to $65\,^{\circ}C$ in $t_3$ minutes,then: