Understanding Uniform Circular Motion

Uniform circular motion is a special type of motion where an object moves in a circular path at a constant speed. While the speed is constant, the direction of the object's velocity is continuously changing as it moves around the circle. Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.

Analysing Statements about Uniform Circular Motion

Let's examine each statement given in the options to determine which one is incorrect about uniform circular motion.

• Statement 1: In Uniform Circular Motion the body moving in circle is accelerating.

  In uniform circular motion, the speed is constant, but the direction of velocity changes at every point. Since velocity is a vector and its direction is changing, the velocity itself is changing. A change in velocity means there is acceleration. This acceleration is called centripetal acceleration and is always directed towards the center of the circle. Therefore, this statement is correct.

• Statement 2: In Uniform Circular Motion the body is changing direction but the speed remains constant.

  This statement accurately describes uniform circular motion. The definition of uniform circular motion is movement in a circular path with constant speed. As the object moves along the circular path, its direction of motion (and thus the direction of its velocity) is continuously changing. Therefore, this statement is correct.

• Statement 4: In Uniform Circular Motion the velocity of body remains constant.

  As discussed, velocity is a vector with both magnitude (speed) and direction. Although the speed (magnitude of velocity) is constant in uniform circular motion, the direction of the velocity is continuously changing. Because the direction is changing, the velocity vector is not constant. Therefore, this statement is incorrect.

• Statement 3: All of the above.

  Since we found that statements 1 and 2 are correct, not all statements are incorrect. Therefore, this option is not the answer representing the incorrect statement.

Identifying the Incorrect Statement

Based on our analysis:

• Statement 1 is correct.
• Statement 2 is correct.
• Statement 4 is incorrect.

The question asks for the incorrect statement about a body undergoing uniform circular motion. The statement that "In Uniform Circular Motion the velocity of body remains constant" is incorrect because the direction of velocity is constantly changing, even if the speed is constant.