Velocity of the particle in uniform circular motion is constant.

Is a satellite moving around the Earth in a circular orbit accelerated? Explain.

An artificial satellite is moving in a circular orbit of radius $36,000 \mathrm{km}$. Calculate its speed if it takes $24$ hours to revolve around the earth. 

Is uniform circular motion an example of accelerated motion? Explain.

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