Question:
What’s the force that lifted the jar of green beans? And why is this force stronger if the sharp end is used?
Answer:
The lifting force is provided by the frictional force exerted by the satay stick on the green beans.
Remember that the (static) friction between two surfaces increases if the two surfaces are pressed more strongly into each other? (f=μN)
When using the sharp end, one can plant the stick into tiny crevices between the beans, resulting in the stick and the beans squeezed tightly against one another. (Imagine a fat man not being able to enter a train vs a not thin lady entering the train and thus making everyone more pressed against one another) The large normal contact forces (horizontal) between the stick and the beans results in large frictional forces (vertical).
The same physics apply to fridge magnets too.
xmPhysics 