Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Work and Energy
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Work and Energy
A simple pendulum consists of a 50 cm long string attached to a 100...
A simple pendulum consists of a long string attached to a ball. The ball is drawn aside until the string forms an angle of 37^{}^{{}^{\circ}} with the vertical, and is subsequently released. Determine the tension in the string when the bob reaches its lowest position.
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
Given , , and \theta = 37^{}^{{}^{\circ}}.
The height descended by the bob from its initial position to the lowest point is:
h = L - L \cos \theta = L(1 - \cos 37^{}^{{}^{\circ}})
Substituting the values, we get:
Using the principle of conservation of mechanical energy, the velocity at the lowest point is given by:
Taking , we have:
At the lowest position, the net force towards the center provides the necessary centripetal acceleration:
Substituting the known values into the equation:
The height descended by the bob from its initial position to the lowest point is:
h = L - L \cos \theta = L(1 - \cos 37^{}^{{}^{\circ}})
Substituting the values, we get:
Using the principle of conservation of mechanical energy, the velocity at the lowest point is given by:
Taking , we have:
At the lowest position, the net force towards the center provides the necessary centripetal acceleration:
Substituting the known values into the equation: