An ideal spring with spring-constant $K$ is hung from the ceiling and a block of mass $M$ is attached to its lower end. The mass is released with the spring initially unstretched. Then the maximum extension in the spring is

What is the acceleration of $3 \,kg$ mass when the acceleration of $2 \,kg$ mass is $2 \,m/s^2$ as shown in the figure? (in $m/s^2$)

$A$ spring with force constant $k$ is cut into two pieces. The length of one piece is twice the length of the other. What is the force constant of the larger piece?

Two identical springs have the same force constant $73.5 \,Nm^{-1}$. The elongation produced in each spring in the three cases shown in Figure-$1$,Figure-$2$,and Figure-$3$ are (given $g=9.8 \,ms^{-2}$):

$A$ body of mass $m$ is tied to one end of a spring and whirled round in a horizontal plane with a constant angular velocity. The elongation in the spring is $1\, cm$. If the angular velocity is doubled,the elongation in the spring is $5\, cm$. The original length of the spring is ......... $cm$

If a spring is extended to length $l,$ then according to Hooke's law,