Question

Can someone please explain rotational motion?

Answer 1

Ans=

Rotational Motion

A system is said to be in pure rotational motion when all the points lying on the system are in circular motion about one common fixed axis. Similar to force, the cause of rotational motion is a physical quantity called a torque. In purely rotational motion, all points on the object move in circles around the axis of rotation (“O”). The radius of the circle is R. All points on a straight line drawn through the axis move through the same angle at the same time. Torque incorporates the following factors.

1. Amount of force.

2. Point of application of force.

3.  The direction of application of force and combining all of the above.

Direction: Direction of torque is given by right-hand thumb rule. If we curl the fingers of the right hand from first vector r to second vector f then right-hand thumb gives us the direction of their cross product.

All torque about same point/axis. If the summation of all torque = 0, then the body is in rotational equilibrium. In the summation of the torque along with force= 0, the body is in mechanical equilibrium