Which type of force is being used in this picture?

 

When the boy pushes the ring, why does the speed of the ring increase?

A hot piece of iron is hammered by a blacksmith. How does the force due to hammering affect it?

Which force is responsible for the attraction between an inflated balloon rubbed with a synthetic cloth and a wall?

Which force acts on a plastic bucket containing water held above the ground in a hand? Why does this force not bring any change in the state of motion of the bucket?

Which two forces immediately act on a rocket fired upwards?