Uniform circular motion is defined by a constant speed even though the direction of movement continuously changes. While the velocity is a vector that changes direction, the speed remains the same at all points along the circular path.

Uniform circular motion means that an object travels along a circular path with a constant speed. Even though the direction of the object's velocity changes, the speed remains fixed, making the first option the correct description.

Uniform circular motion occurs along a circle with an unchanging radius. This fixed distance from the center is one of the defining characteristics of circular motion, making the radius constant throughout.

In uniform circular motion, the magnitude of the velocity, which is the speed, remains constant even though the velocity vector itself is continually changing direction. The other options refer to vector quantities whose directions are always changing.

The word 'uniform' indicates that the object maintains a constant speed throughout its motion along the circular path. Although the object's velocity changes due to a changing direction, its speed remains uniform, which is why constant speed is the correct answer.

In uniform circular motion, the angular velocity (ω = v/r) remains constant if both the speed and radius are unchanging. While the direction of the velocity and acceleration vectors continuously varies, the rate at which the object sweeps out angles remains fixed.

When speed and radius are constant, the magnitude of the centripetal acceleration, given by v²/r, remains the same throughout the motion. Although its direction changes as the object moves, its magnitude does not, making it the correct answer.

Since the mass, speed, and radius are fixed in uniform circular motion, the magnitude of the centripetal force (m*v²/r) remains constant. Its direction, however, continuously changes as it always points toward the center of the circle.

With a constant speed and fixed radius, the angular velocity (ω = v/r) calculated for the car remains unchanged throughout its motion. Although the car's velocity and acceleration directions change constantly, the angular velocity does not.

The key characteristic of uniform circular motion is that the speed, or the magnitude of the velocity, remains constant. Even though the velocity vector changes direction, its magnitude does not vary, making it the correct answer.

In uniform circular motion the centripetal acceleration is always directed toward the center of the circle; its magnitude (v²/r) remains constant when speed and radius are constant. However, the direction of this acceleration changes continuously as the object moves.

The linear speed and angular speed in circular motion are related by the formula ω = v/r. This means that if both v and r are constant, then ω remains constant as well. The other options do not correctly express this relationship.

Given that the radius and linear speed are constant, the period T (the time required for one complete revolution) calculated by T = 2πr/v will also be constant. Other quantities, such as instantaneous displacement or velocity direction, change continuously.

The centripetal force always acts perpendicular to the displacement of an object in uniform circular motion. Because work is the component of force in the direction of displacement, the work done by a perpendicular force is zero.

The constant radius is a defining characteristic of uniform circular motion. While other measurements along the path, such as chord lengths or arc segments over time, may vary depending on the position, the radius remains unchanged.

Doubling the speed while keeping the radius constant increases the centripetal acceleration by a factor of four, since a = v²/r. The particle's mass and the radius remain unchanged, and the motion can still be uniform even though the acceleration magnitude is different.

Angular speed is given by ω = v/r. For Object A it is v/r, and for Object B it is (2v)/(2r), which simplifies to v/r as well. Although their linear speeds and centripetal accelerations differ, their angular speeds are identical.

Assuming the velocity does not change in direction implies that there is no acceleration, since acceleration is the rate of change of velocity. In reality, even though the speed is constant, the continuous change in the direction of the velocity vector produces a centripetal acceleration.

With a constant angular speed, the angular displacement increases linearly over time, following the relation θ = ωt. Even though the object may return to its starting position after a complete cycle, the total angular displacement keeps accumulating.

The period T, defined as the time required for one complete revolution, is a fixed value in uniform circular motion when speed and radius are constant. In contrast, the instantaneous displacement, velocity, and momentum vectors continually change as the object moves along the circle.