A block of mass 2 kg is moving with speed v0 towards a massless unstreched spring (K=10N/m). It is found that for maximum speed v0=√6.4m/s, the block compresses the spring, stops at that position and does not return back. Friction coefficient at surface is μ=1x.Value of x is
x=μmgK12mv2=kx22+μmg(1+x)
answer: 5