A. Angular acceleration
A.
B. Centripetal acceleration
B.
C. Linear velocity
C.
D. Displacement
D.
Correct Answer: A
সঠিক উত্তর: A
Explanation
ব্যাখ্যা
In uniform circular motion, an object moves in a circular path at a constant speed. Let's evaluate each option:
Angular acceleration: Angular acceleration is the rate of change of angular velocity. In uniform circular motion, the angular velocity is constant because the object covers equal angles in equal time intervals. Therefore, angular acceleration is always zero.
Centripetal acceleration: Centripetal acceleration is the acceleration directed toward the centre of the circle, necessary for changing the direction of motion. It is given by, , where is the linear speed, and is the radius. Since linear speed is constant, centripetal acceleration is always non-zero.
Linear velocity: Linear velocity (or tangential velocity) has a constant magnitude but a changing direction. Its magnitude is given by , which is constant and non-zero. Therefore, linear velocity is never zero.
Displacement: Displacement is the change in position from the initial to the final point. Over any time interval that is not a multiple of the period (the time for one full circle), the displacement is non-zero.
Thus, the quantity that is always zero in uniform circular motion is angular acceleration.
