Question
Read the following statements and pick up the true and false statements:
(a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre.
(b) The change in velocity vector of a particle in uniform circular motion in one complete cycle is zero vector.
(c) The magnitude of the change in acceleration vector in uniform circular motion over half cycle is zero.
Solution
(a) False; the statement is true if the motion is uniform circular motion.
It the speed of particle increases or decreases, then there will be tangential acceleration also. Therefore, the net acceleration will subtend some angle with the radius.
(b) True; because in uniform circular motion the speed of particle is constant and direction of motion is given by drawing the tangent to the circle at that point.
Since after completing one cycle the particle again comes at the same point, therefore, the direction of motion and speed is same and hence the velocity is same.
Therefore, change in velocity is zero.
(c) False; the acceleration of a particle at any point is directed towards the centre at that point.
At A,
Hence, not zero.
It the speed of particle increases or decreases, then there will be tangential acceleration also. Therefore, the net acceleration will subtend some angle with the radius.
(b) True; because in uniform circular motion the speed of particle is constant and direction of motion is given by drawing the tangent to the circle at that point.
Since after completing one cycle the particle again comes at the same point, therefore, the direction of motion and speed is same and hence the velocity is same.
Therefore, change in velocity is zero.
(c) False; the acceleration of a particle at any point is directed towards the centre at that point.
At A,
Hence, not zero.
