Centripetal Force and Direction of Motion

• A person is spinning a ball tied to a string in a circular path.
• Midway, the person releases the string.
• As soon as the string is released, the ball moves off in a straight-line path tangent to the circular motion.

🧠 Physics Concept:

This video is a classic demonstration of centripetal force and inertia.

1. While the ball is spinning:

• • The string provides a centripetal force, constantly pulling the ball toward the center.
  • This force is what keeps the ball moving in a circular path.

1. At the moment the string is released:

• • The centripetal force suddenly disappears.
  • According to Newton’s First Law (inertia), the ball continues in a straight-line motion tangent to the circle at the point of release.
  • This shows that the ball was not "feeling" a centrifugal force pushing it outward; it was the absence of inward force that causes it to move in a straight line.

🧲 Key Physics Takeaways:

• Centripetal Force is needed for circular motion; it acts inward.
• When this force is removed, the object moves in a straight line (not curved), following its tangential velocity.
• This directly supports Newton’s Laws and the nature of non-inertial frames.