The arm is perpendicular to the axis of rotation. If you look at the axis along its axis it is only a point. The torque is force times distance tot that point
Measure the angle in a plane perpendicular to the axis of rotation, between the position of a fixed point at the start and end of the rotation.
They are faces such that the perpendicular distance between them is the same wherever on either face you measure it.
A degree is a measure of rotation, a foot is a measure of distance. These two are incomparable.
An inch is a measure of linear displacement (distance) while a degree is a measure of angular displacement (rotation). There is no constant relationship between the two. The same angular displacement will result in a bigger linear displacement the further you are from the centre of rotation.
Yes, if you rotate something you are only turning it, you are not affecting its size.
A moment, also known as torque, is a measure of the tendency of a force to cause an object to rotate around an axis or point. It is calculated by multiplying the magnitude of the force by the perpendicular distance from the line of action of the force to the axis of rotation. The moment of a force is the product of the force and the perpendicular distance from the point of rotation to the line of action of the force. It is a vector quantity that describes how much a force tends to make an object rotate. Moments are important in physics and engineering for understanding the effects of forces on objects and structures.
90 degrees
:parallax error occurs when the line of sight or measure is not at right angles ( perpendicular ) to the objects being measured. Any distance between the object and the measuring reference ( for example a rule ) will cause a misreading. This error will increase as the distance between the object and the reference increases.
There can be no equivalence. A kilometre is a measure of linear displacement while a degree [rotation] is a measure of angular displacement. The two measure different things and, according to basic principles of dimensional analysis, any attempt at conversion from one to the other is fundamentally flawed. For any angular rotation, the linear displacement is directly proportional to the distance from the centre of rotation.
Displacement is a measure of distance. Speed is a measure of the RATE at which the distance is traversed.
Angstroms
With maths and light brightness.... Distance between two points...