Final answer:
On a perfectly smooth, frictionless icy surface, the arrows and forces representing friction decrease to nearly zero. Once the force stops after accelerating the crate, the crate's acceleration becomes zero, but it will continue to move at a constant speed due to inertia.
Step-by-step explanation:
If a crate is on ice, assuming the ice is perfectly smooth and frictionless, the arrows and forces representing friction would decrease or become essentially non-existent. This is because the coefficient of friction on ice is much lower than on rougher surfaces, ultimately approaching zero if the ice is perfectly smooth and there is no other form of resistance.
When a force is applied to accelerate the crate and then stops, the crate's acceleration would become zero because no additional forces are acting on it. However, due to inertia, the crate would continue to move at a constant velocity until another force acts on it to change its state of motion.
When the surface that the crate is on is ice, the friction between the crate and the surface is reduced to almost zero. This means that there is little or no resistance to the crate's motion. As a result, the arrows and forces acting on the crate remain unchanged.