Question

After the student pushes on the wall, the student moves to the right. Based upon the forces you selected as present above, which explanation best explains the motion of the student?

a) The motion of the student is best explained by Newton's Third Law. As the student pushes on the wall, the wall pushes back on the student. Because the force from gravity is balanced by the force of the floor, the only force present on the skateboard and the student is the force applied by the wall on the student.
b) The motion of the student is best explained by Newton's First Law. The student is at rest until a force is applied against the wall. The push of the student against the wall is directly responsible for the motion of the student.
c) The motion of the student is best explained by Newton's Second Law. The wall does not move when the student pushes on it; however, the student does move due to the relatively small mass of the student.

Answer 1

The motion of the student moving to the right after pushing against the wall is best explained by Newton's Third Law of motion, wherein the wall exerts an equal and opposite reaction force propelling the student.

Step-by-step explanation:

When the student pushes against the wall and subsequently moves to the right, the best explanation for this motion comes from Newton's Third Law of motion. This law states that for every action, there is an equal and opposite reaction. So, when the student exerts a force on the wall, the wall exerts an equal and opposite force on the student. Since the force from gravity is balanced by the normal force from the floor, and assuming there's no friction involved, this reaction force from the wall is what propels the student to move to the right.