A toy car of mass $80 \mathrm{g}$ is maintained to move in a horizontal circle of radius $0.8 \mathrm{m}$ with a velocity $v \mathrm{m} {\mathrm{s}}^{-1}$. If the centripetal force acting on it is $10 \mathrm{N}$, then the value of $v$ in $\mathrm{m} {\mathrm{s}}^{-1}$ is

A car of mass $200 \mathrm{kg}$ is revolving in a circular track of radius $70 \mathrm{m}$ with angular velocity $0.2 \mathrm{rad} {\mathrm{s}}^{-1}$, then find the centripetal force in Newton.

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

 Compare the magnitudes of centripetal and centrifugal force.

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,