If $r_p, v_p, L_p$ and $r_a, v_a, L_a$ are radii, velocities and angular momenta of a planet at perihelion and aphelion of its elliptical orbit around the Sun respectively, then
The total energy of a satellite in a circular orbit at a distance $(R+h)$ from the centre of the Earth varies as [ $R$ is the radius of the Earth and $h$ is the height of the oribit from Earth's surface]
Two wires A and B are made of same material. Their diameters are in the ratio of $1: 2$ and lengths are in the ratio of $1: 3$. If they are stretched by the same force, then increase in their lengths will be in the ratio of
A horizontal pipe carries water in a streamlined flow. At a point along the pipe, where the cross-sectional area is $10 \mathrm{~cm}^{-2}$, the velocity of water is $1 \mathrm{~ms}^{-1}$ and the pressure is 2000 Pa . What is the pressure of water at another point where the cross-sectional area is $5 \mathrm{~cm}^2$ ?
[Density of water $=1000 \mathrm{kgm}^{-3}$ ]