Which statement best describes uniform circular motion in the context of motion and force?
An object moves in a circle at constant speed but its velocity changes due to change in direction.
Speed is a scalar quantity, but velocity is a vector - it has both magnitude and direction. In uniform circular motion the magnitude (speed) is fixed, yet the direction of motion is tangential to the circle and therefore changes from instant to instant.
Because the direction of velocity keeps changing, the velocity itself is not constant, even though the speed is. This changing velocity means the body is accelerating.
The acceleration is directed towards the centre of the circle and is called centripetal acceleration, produced by a net centripetal force (for example, tension in a string or gravitational pull).
A straight-line path with changing speed is not circular, while a circular path cannot have a truly constant direction of velocity, so the other options are physically inconsistent.
Hence, in uniform circular motion an object moves in a circle at constant speed but its velocity changes due to a continuous change in direction.
Similar Questions
Which of the following describes the rate at which an object changes its velocity?
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Which of the following statements best defines uniform circular motion?
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Important Questions from Motion in a Straight Line
- Which of the following examples represents motion along a straight line?
Ram records the odometer readings of his car for the distance covered from 2000 km at the start of his journey and 2400 km at the end of the journey after 8 hours. What is the average speed of the car?
A body moves along a straight line with displacement \(s = 4t^2 + 2ts =4t^2+2ts=4t^2+2t\) (in m, t in s). Its instantaneous acceleration is:
The area under a velocity-time graph between two instants represents:
A body is dropped freely from a height 'X' m. If tit takes Y seconds to reach the ground. The time it takes to reach half of the height of the tower is (Take g = 10m/s2)
