A small ring of mass 'm'is attached on one end of a light string of le...
A small ring of mass 'm'is attached on one end of a light string of le...
Analysis:
To solve this problem, we will use the principle of conservation of mechanical energy. The total mechanical energy of the system (ring and block) is conserved when the string becomes vertical.
Initial State:
In the initial state, the block B is at rest and the ring is attached to it. The system has potential energy due to the height of the block above the ground and no kinetic energy.
Final State:
When the string becomes vertical, the block B has fallen a distance equal to the length of the string. At this point, the block B has reached its maximum velocity and the ring has zero velocity.
Conservation of Mechanical Energy:
Since there is no external force acting on the system (neglecting air resistance), the total mechanical energy of the system is conserved. This means that the initial mechanical energy is equal to the final mechanical energy.
Initial Mechanical Energy:
The initial mechanical energy of the system is given by the potential energy of the block B due to its height above the ground. The potential energy is given by the equation: PE = mgh, where m is the mass of the block B, g is the acceleration due to gravity, and h is the height of the block above the ground.
Final Mechanical Energy:
The final mechanical energy of the system is given by the kinetic energy of the block B. The kinetic energy is given by the equation: KE = (1/2)mv^2, where m is the mass of the block B and v is its velocity.
Equating Initial and Final Mechanical Energies:
Setting the initial mechanical energy equal to the final mechanical energy, we have: mgh = (1/2)mv^2.
Simplifying the Equation:
Since the mass of the block B cancels out, we are left with: gh = (1/2)v^2.
Solving for Velocity:
To find the velocity v, we can rearrange the equation as follows: v^2 = 2gh.
Taking the square root of both sides: v = √(2gh).
Substituting Values:
Substituting the given values into the equation, we have: v = √(2 * 10 * 0.6) = √(12) = 3.46 m/s.
Final Answer:
The velocity of the ring when the string becomes vertical is 3.46 m/s.
To make sure you are not studying endlessly, EduRev has designed Class 11 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 11.