A bead can slide on a smooth wire and particle of mass m is attached to the bead by a light string of length L. The particle is held in contact with the wire with the string taut and is then let fall. The bead has mass 3 m.Kinetic Energy of the bead, when the string is vertical will be
Question
A bead can slide on a smooth wire and particle of mass m is attached to the bead by a light string of length L. The particle is held in contact with the wire with the string taut and is then let fall. The bead has mass 3 m.Kinetic Energy of the bead, when the string is vertical will be
Solution
To solve this problem, we need to use the principle of conservation of energy. This principle states that the total energy of an isolated system remains constant if no external forces act on it. In this case, the system is the bead and the particle, and we can assume that no external forces are acting on it.
Step 1: Initial Energy Initially, the particle is held in contact with the wire with the string taut. So, the initial potential energy of the system is mgL (mass of the particle times gravity times the length of the string). The bead is at rest, so its initial kinetic energy is 0.
Step 2: Final Energy When the string is vertical, the particle has fallen a distance L, so its final potential energy is 0. The bead has moved, so it has some kinetic energy, which we'll call K.
Step 3: Conservation of Energy According to the conservation of energy, the initial energy of the system equals the final energy. So, we have:
mgL = 0 + K
Solving for K, we get:
K = mgL
However, the kinetic energy of the bead is not K, but a fraction of K, because the bead has mass 3m. The kinetic energy of an object is given by the formula (1/2)massvelocity^2. Since the bead and the particle are connected by a string, they have the same velocity. So, the kinetic energy of the bead is (1/2)3mvelocity^2.
Step 4: Equating Energies We can equate the kinetic energy of the bead to the potential energy lost by the particle to find the velocity:
(1/2)3mvelocity^2 = mgL
Solving for velocity, we get:
velocity = sqrt((2gL)/3)
Step 5: Kinetic Energy of the Bead Substituting this velocity back into the kinetic energy equation, we get:
Kinetic Energy of the bead = (1/2)3mvelocity^2 = (1/2)3m((2gL)/3) = mgL
So, the kinetic energy of the bead when the string is vertical is mgL.
Similar Questions
A bead can slide on a smooth wire and particle of mass m is attached to the bead by a light string of length L. The particle is held in contact with the wire with the string taut and is then let fall. The bead has mass 3 m.Vertical component of velocity of mass m, when the string makes angle 30o with wire will be
A body of mass 1 kg tied to a string is just able to move in a vertical circular path of the radius 1 m. The difference between the kinetic energies at its highest and lowest positions of the body is45√ J20 J 10 J 30 J
A bead starts sliding from a point P on a frictionlesswire with initial velocity of 5 ms –1 . Find thevelocity of bead at point R (take g = 10 ms –2 )(1) 7 m/s(2) 5 2 m/s 4 mPRQ1.65 m(3) 6 2 m/s(4) 6 m/s
A bob of mass ' m ' is suspended by a light string of length ' L '. It is imparted a minimum horizontal velocity at the lowest point A such that it just completes half circle reaching the top most position B. The ratio of kinetic energies ( K.E. )A( K.E. )B is :
A body of mass M tied to a string is lowered at a constant acceleration of (g/4) through a vertical distance h. The work done by the string will be :-MghMghMghMgh
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.