Question

For a particle moving in a circle with constant angular speed, which of the following statements is 'false'?

• A. The velocity vector is tangent to the circle.
• B. The acceleration vector is tangent to the circle.
• C. The velocity and acceleration vectors are perpendicular to each other.
• D. The acceleration vector points to the centre of the circle.

Hint:

Constant speed = No Tangential Acceleration. The only "pull" is toward the center to keep the particle turning.

Answer 1

The Correct Option is B

Step 1: Concept
In Uniform Circular Motion (UCM), the angular speed ($\omega$) is constant, meaning there is no tangential acceleration ($a_t = 0$).

Step 2: Meaning
The only acceleration present is centripetal acceleration ($a_c$), which always points toward the center of the circle.

Step 3: Analysis
- (A) True: Velocity is always tangential.
- (B) False: Tangential acceleration is zero in UCM; the acceleration is radial, not tangent.
- (C) True: Radial acceleration is perpendicular to tangential velocity.
- (D) True: Centripetal acceleration points to the center.

Step 4: Conclusion
Statement (B) is false for constant angular speed. Final Answer: (B)