# The angular acceleration of a body, moving along the circumference of a circle, is

The angular acceleration of a body, moving along the circumference of a circle, is :

1. Along the axis of rotation

2. Along the radius, away from centre

3. Along the radius towards the centre

4. Along the tangent to its position

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The correct answer is (4): Along the tangent to its position.

Explanation :

Angular acceleration is caused by torque, which can be calculated using the formula τ = I × α, where τ represents torque and α represents angular acceleration. The moment of inertia, denoted by I, is a property of the object in motion.

Consider a circular plane with a body moving along its circumference. The torque acting on the body can be expressed as τ = r × F, where r represents the radius and F represents the perpendicular force tangent to the circle.

The direction of torque is perpendicular to both r and F, as both vectors lie perpendicular to the circle. Since the two vectors lie within the same plane, their cross product lies on the perpendicular axis. Consequently, if the torque acts on the perpendicular axis of the plane, the angular acceleration will also occur along the perpendicular axis.

Therefore, the correct answer is option 4: the angular acceleration lies tangent to the body’s position.

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