The physical quantity having the dimensions of the square root of the ratio of the kinetic energy and surface tension is

If the displacement ( $s$ in metre) of a moving particle in terms of time $(t$ in second $) s=t^3-6 t^2+18 t+9$, then the minimum velocity attained by the particle is

If a force $(\beta \hat{\mathbf{i}}+2 \hat{\mathbf{j}}+5 \hat{\mathbf{k}}) \mathrm{N}$ acting on a body displaces it through $(2 \hat{\mathbf{i}}+2 \hat{\mathbf{j}}+1 \hat{\mathbf{k}}) \mathrm{m}$, then the work done by the force on the body is

If two bodies $A$ and $B$ are projected with same velocity but with different angles $\theta_1$ and $\theta_2$ respectively with the horizontal such that both will have same range, then the ratio of times of flight of the bodies $A$ and $B$ is