If you see an object rotating, is there necessarily net torque acting on it? Explain
When you see an object rotating, there is not necessarily a net torque acting on it. The rotation of an object is a result of the balance between the external torques applied to it. If there is no net torque acting on an object, it would be in rotational equilibrium and keep rotating at a constant speed.
To understand whether there is a net torque acting on an object or not, you can follow these steps:
1. Identify the external forces: Start by identifying all the external forces acting on the object. These forces can include gravity, applied forces, friction, etc.
2. Determine the lever arm: For each external force, determine the perpendicular distance between the axis of rotation (the point where the object rotates around) and the line of action of the force. This distance is called the lever arm.
3. Calculate the torque: To calculate the torque exerted by each force, multiply the magnitude of the force by the magnitude of the lever arm.
4. Sum the torques: Add up the torques from all the external forces acting on the object. If the sum of the torques is zero, then there is no net torque. If there is a nonzero sum, then there is a net torque acting on the object.
So, when you observe an object rotating, the presence or absence of net torque depends on whether the sum of all the torques acting on it is zero or not.
Is the Earth Rotating?
net torque means it is accelerating...