Physics XI Content
CIRCULAR MOTION-ANGULAR MOTION-RADIAN
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CIRCULAR MOTION-ANGULAR MOTION-RADIAN
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UNIFORM CIRCULAR MOTION
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| When an object moves in a circular path such that the magnitude of velocity is constant then, the motion is called uniform circular motion. | |||
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ANGULAR MOTION
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| When a body moves along a circular path it traverses a certain angle in a given interval of time. This type of motion is called ‘angular motion‘. | |||
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ANGULAR DISPLACEMENT
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| “The angle traveled by a body during its motion around a circular path is called its angular displacement.” Consider a particle moves in a circular path from a point P1 to P2 in an interval of time Dt. It travels an angle <p1OP2 = q which is called angular displacement of the particle. |
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RADIAN
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| One radian is the angle traced by an arc of length equal to radius of circle. Length of circular track of radius r is 2p r. Therefore, numbers of radians in a circle of radius r will be =2p r / r = 2pAngle at the centre of circle in one complete rotation = 360o = 2p rad 180o = p rad or 1o = p / 180 rad. |
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| RELATION BETWEEN LENGTH OF ARC AND THE ANGLE SUBTENDED | |||
| The length of arc “S” is directly proportional to angle q subtended (measured in radians) traced at the centre of circle by ends of the arc. | |||
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S a q
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S = rq
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| Where r is radius of circle. | |||