Question

question 2 of 10 which of the following happens to an object in uniform circular motion? a. its speed changes. b. its centripetal acceleration changes. c. the direction of its velocity stays the same. d. its velocity changes.

Explanation:

Step1: Define uniform circular motion

In uniform circular motion, speed is constant. But velocity is a vector quantity having both magnitude (speed) and direction.

Step2: Analyze velocity

The direction of velocity in uniform - circular motion is always tangent to the circle. As the object moves along the circle, the direction of the velocity vector changes continuously.

Step3: Analyze centripetal acceleration

Centripetal acceleration $a_c=\frac{v^2}{r}$ has a constant magnitude in uniform circular motion (since $v$ and $r$ are constant), but its direction always points towards the center of the circle. So, its direction changes as the object moves.

Answer:

D. Its velocity changes.