Which of the following is a natural polymer?

If $(2,-1,3)$ is the foot of the perpendicular drawn from the origin to the plane,then the equation of the plane is

When a body of mass $1.0\, kg$ is suspended from a certain light spring hanging vertically,its length increases by $5\, cm$. By suspending a $2.0\, kg$ block to the spring,if the block is pulled through $10\, cm$ and released,the maximum velocity in $m/s$ is: (Acceleration due to gravity $g = 10\, m/s^2$)

$A$ gramophone record is revolving with an angular velocity $\omega$. $A$ coin is placed at a distance $r$ from the centre of the record. The static coefficient of friction is $\mu$. The coin will revolve with the record if

Statement$-1$ : Toluene is more reactive than benzene in chlorination.
Statement$-2$ : During the nitration of Toluene $\stackrel{\oplus}{ N } O _2$ acts as electrophile.