The woman is pushing a cart through the store and she applied to much force to the cart and all of the stuff came out of the cart. This is repersenting Newton's 1st law becuase the food that is in motion wants to stay in motion.
When she hit the bar the cart bounced back at her becuase the poll pushed back at the cart. this is repersenting Newton's 3rd law becuase every action has an equal and oppisite reaction.
if I want to start to push the cart again I would have to accelerate and that involves exerting more force on the object. This involves Newton's 2nd law.