Question

an object is undergoing a uniform circular motion. what can one say about its acceleration? multiple choice impossible to determine since the speed of the rotating object is not given. the acceleration has a constant magnitude, but its direction changes continuously. the acceleration is constant in both magnitude and direction. the acceleration has a constant direction, but its magnitude changes continuously.

Explanation:

In uniform circular motion, speed (magnitude of velocity) is constant, but velocity direction (tangent to circle) changes. Acceleration (centripetal) has magnitude $a = \frac{v^2}{r}$ (constant for constant $v, r$) and direction towards the center, which changes as the object moves, so direction is not constant.

Answer:

B. The acceleration has a constant magnitude, but its direction changes continuously.