A ball is suspended from the top of a cart by a string of length $1.0\mathrm{ }\mathrm{m}$. The cart and the ball are initially moving to the right at constant speed $V$ as shown in figure $\left(1\right)$. The cart comes to rest after colliding and sticking to a fixed bumper, as in figure $\left(2\right)$. The suspended ball swings through a maximum angle $60°.$ The initial speed $V$ is $($take $g=10 \mathrm{m} {\mathrm{s}}^{-2})$,

 

The spring block system lies on a smooth horizontal surface. The free end of the spring is being pulled towards right with constant speed $v_0=2\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}$. At $t=0 \mathrm{s}$, the spring of constant $k=100 \mathrm{N} {\mathrm{cm}}^{-1}$ is unstretched and the block has a speed $1 \mathrm{m} {\mathrm{s}}^{-1}$ to left. The maximum extension of the spring is,

One of the forces acting on a particle is conservative then which of the following statement(s) are true about this conservative force?