Answer:
Newton's 1st law explains this reaction
Step-by-step explanation:
Newton's first law of motion, states that " a body at rest or uniform motion in a straight line, will continue in that state, unless acted upon by an external force.
The coffee in the cup, initially rest on the table, but the moment you bump the table, you act as an external force which distort the initial state of the coffee, making it to spill out.
Therefore, Newton's 1st law explains this reaction.