Final answer:
If a person pushes on a beam with a high magnitude of force, the beam will accelerate, following Newton's Second Law of Motion, assuming the beam's structural integrity is not compromised.
Step-by-step explanation:
When a person pushing on a beam uses a high magnitude of force, the beam will accelerate. According to Newton's Second Law of Motion, the acceleration of an object is directly proportional to the net applied force and inversely proportional to the object's mass. In other words, if the beam's mass remains constant, an increase in the applied force will result in an increase in the beam's acceleration. This is assuming the beam doesn't reach its structural limits and break or other external factors are not at play that could influence the motion such as friction or air resistance.