One end of a massless spring of constant 100N/m and natural length 0.5m is fixed and the other end is connected to a particle of mass 0.5kg lying on a frictionless horizontal table. The spring remains horizontal. If the mass is made to rotate at angular velocity of 2 rad/s, then elongation of spring is

What is an artificial satellite? Name any two types of artificial satellite and state their functions.

A small block of mass $100 \mathrm{g}$ is tied to a spring of spring constant $7.5 \mathrm{N} {\mathrm{m}}^{-1}$ and length $20 \mathrm{cm}.$ The other end of spring is fixed at a particular point $A.$ If the block moves in a circular path on a smooth horizontal surface with constant angular velocity $5 \mathrm{rad} {\mathrm{s}}^{-1}$about point $A,$ then tension in the spring is

Two stones of masses $m$ and $2m$ are whirled in horizontal circles, the heavier one in radius $\frac{r}{2}$ and the lighter one in radius $r$. The tangential speed of lighter stone is $n$ times that of the tangential speed of the heavier stone. They are reported to experience the same centripetal force. The value of $n$ is, 

The earth revolves around the sun in an orbit of radius $1.5\times {10}^{11} \mathrm{m}$ once in a year. Calculate the centripetal acceleration of the earth.

In hydrogen atom, the electron is moving round the nucleus with velocity $2.18\times {10}^6 \mathrm{m}{\mathrm{s}}^{-1}$ in an orbit of radius $0.528 \mathrm{Å}$. The acceleration of the electron is