if I sit a bag of groceries on the kitchen table or counters , no matter how I place the bag , 90% will end up on the floor , I can even sit a bag of groceries inside the kitchen sink and every thing in that bag will roll up the side of the sink , across the counter onto the floor where it will continue roll clear across the floor until it comes to rest under the refrigerator
that includes boxes , they'll roll under the refrigerator as well
thats my one rule of Physics