The correct option is (c).
Explanation
Motion is characterized by the change in position of an object with respect to time. It is described using physical quantities such as distance, displacement, speed, and velocity. The nature of the path and the constancy of these quantities determine whether the motion is uniform, non-uniform, or circular.
Statement-wise Analysis:
- Statement 1 is Incorrect.
Uniform motion is defined as motion in which a body covers equal distances in equal intervals of time. In physics, unless specified otherwise, "uniform motion" typically implies uniform velocity, which requires motion in a straight line. It is not restricted to a circular path. Even if interpreted as uniform speed, the path can be straight, curved, or irregular, not necessarily circular. - Statement 2 is Correct.
Uniform Circular Motion (UCM) is specifically defined as the motion of an object traveling at a constant speed along a circular path. While the speed remains constant, the velocity changes continuously due to the change in direction. The trajectory is strictly a circle. - Statement 3 is Correct.
Displacement is a vector quantity representing the shortest straight-line distance from the initial position to the final position. It depends solely on the starting and ending points and is independent of the actual path taken by the object. In contrast, distance is a scalar quantity that depends on the total path length covered.
Key Takeaway:
Displacement is a state function dependent only on initial and final positions (path-independent), whereas distance is path-dependent. Uniform motion generally implies a straight-line path with constant velocity, while uniform circular motion specifically refers to a circular path with constant speed.