Topic: Engineering Mechanics
A thin circular disc is rolling with a uniform linear speed, along a straight path on a plane surface. Consider the following statements in this regard-
1. All points of the disc have the same velocity
2. The center of the disc has zero acceleration.
3. The center of the disc has centrifugal acceleration.
4. The point on the disc making contact with the plane surface has zero acceleration
Of these statements
- A. 1 and 4 are correct
- B. 3 and 4 are correct
- C. 3 alone is correct
- D. 2 alone is correct
Answer: D. 2 alone is correct
Explanation: In pure rolling with uniform linear speed: 1. Velocity varies at different points due to the combination of translation and rotation. 2. The center of the disc moves with uniform velocity, hence it has zero acceleration. 3. Since it has zero acceleration, there is no centrifugal acceleration at the center. 4. The point of contact has zero velocity, but it has a non-zero normal acceleration directed towards the center. Therefore, only statement 2 is correct.