v≤μrgv \leq \sqrt{\mu \mathrm{rg}}v≤μrg
v≤(μrg)v \leq(\mu \mathrm{rg})v≤(μrg)
v>μrgv>\mu \mathrm{rg}v>μrg
v>μrg\mathrm{v}>\sqrt{\mu \mathrm{rg}}v>μrg
