Question

Page 69 Section Review 3-1,3-) When an acrobat reaches the equilibrium position, the net force acting along the direction of motion is zero. Why does the acrobat swing past the equilibrium position?

According to the 1st law of motion (the law of inertia), the acrobat past the equilibrium position because he/she is initially in motion.
(or it gains momentum as approaching to equilibrium position and pass there with that momentum)

Answer 1

The acrobat swings past the equilibrium position because of the force of gravity acting on the acrobat and the inertia of the acrobat's movement. When the acrobat reaches the equilibrium position, the net force acting along the direction of motion is zero, but the acrobat still has momentum from its initial movement. This momentum causes the acrobat to continue moving past the equilibrium position. In addition, the force of gravity also pulls the acrobat downward, contributing to its movement past the equilibrium position