A stone tied to a string is whirled in a horizontal circle. Explain the motion of the stone when the string breaks. 

• Before the String Breaks:
  • The stone is kept in a circular path by the tension in the string, which provides the necessary centripetal force directed towards the center of the circle.
  • The stone continuously changes direction as it moves along the circular path, but the tension in the string ensures it stays in the circle.
• At the Moment the String Breaks:
  • The centripetal force disappears immediately because the tension in the string is no longer present.
  • Without this force, there is nothing to keep the stone moving in a circular path.
• After the String Breaks:
  • According to Newton’s First Law of Motion (inertia), an object in motion will continue in motion with the same speed and in the same direction unless acted upon by an external force.
  • Therefore, the stone will move in a straight line tangent to the circle at the point where the string breaks. This path is called a tangential path.
  • The stone’s velocity at the moment the string breaks determines the direction of this straight-line motion.

Dr. Bbosa Science