If $3$ is a root of $x^2+kx-24=0$,then it is also a root of which of the following equations?

$A$ body $A$ starts from rest with an acceleration $a_1$. After $2 \ s$,another body $B$ starts from rest with an acceleration $a_2$. If they travel equal distance in the $5^{th} \ s$ after the start of $A$,then the ratio $a_1 : a_2$ is equal to

If $a, b$ and $c$ form a geometric progression with common ratio $r$,then the sum of the ordinates of the points of intersection of the line $ax + by + c = 0$ and the curve $x + 2y^2 = 0$ is

The major product of the following reaction is

$A$ uniform chain of length $L$ is lying on a horizontal table. If the coefficient of friction between the chain and the table top is $\mu$,what is the maximum length of the chain that can hang over the edge of the table without disturbing the rest of the chain on the table?