Answer:
So it gets to the top of the ramp and stops. The parallel force pushing it down the ramp is mg sin θ, but for it to move, the frictional force must be overcome. This frictional force is μmg cos θ, where μ is the coefficient of static friction. For movement, then,
mg sin θ > μmg cos θ ==> tan θ > μ ==> θ > arctan 0.5 = 26.565° ==> θ = 27°