explain why a child on a swing comes to rest directly below the top of the swinng

When a child is on a swing, several forces are acting on them, including gravity, tension in the swing's chains or ropes, and air resistance. The position where the child comes to rest directly below the top of the swing is related to the conservation of mechanical energy.

As the child swings back and forth, their potential energy (stored energy due to height above the ground) is constantly converting to kinetic energy (energy of motion) and vice versa. At the highest point of the swing, the child's kinetic energy is at its minimum, and their potential energy is at its maximum. This happens because the child temporarily stops moving momentarily before reversing direction.

As the swing begins to move downward, gravity pulls the child downward, converting their potential energy into kinetic energy. The force of gravity increases their speed, and once they reach the lowest point of the swing, their potential energy is at its minimum, and their kinetic energy is at its maximum.

As the child swings back upward towards the top of the swing, gravity slows them down, converting their kinetic energy back into potential energy. At the topmost point, all of their kinetic energy is converted back into potential energy, and for an instant, their speed reaches zero.

Due to inertia, the tendency of an object to resist changes in its state of motion, the child continues moving upward slightly after reaching the highest point of the swing. However, because their speed is momentarily zero at the top, there is no force pushing them to one side or another, and they come to rest momentarily. At this point, the child is directly below the top of the swing.

This phenomenon occurs since the unbalanced forces acting on the child are momentarily zero when they reach the topmost point of the swing, resulting in a brief pause or rest directly below the top.