Introduction to Momentum
Momentum is an important concept to understand in weight lifting. Momentum simply describes the ability of an object to move with the velocity that it initially has. In physics, momentum is a term involving the entire property of a system, and thus it refers to how the system is structured or located after a time. The momentum can be defined as the ability of an object to change its position in one direction, or to continue moving in the forward direction without changing direction.
Momentum is directly related to torque, which describes the movement of an object with its velocity and direction. Because of the angular momentum of the system, a change in the velocity or direction will result in the alteration or transformation of moments. The sum of all moments, referred to as the resultant, is equal to the total force of motion. Thus, the amount of torque or force acting on an object must balance the amount of momentum that is being produced, and the resultant is a net amount of force that acts in the opposite direction.
Momentum and torque are not the same concept, however. Momentum relates only to the magnitude of forces that act on an object. Torque, on the other hand, relates only to the magnitude of potential energy. Potential energy is a scalar, while both forces are real and measurable. Thus, the formula for determining Momentum and Torque is
To calculate the moments of an object, you need two things: the path of the force and the tangent line connecting the force to the line. By knowing the path of the force, you can calculate the tangent, or straight line between the two points. This gives the moment that the object experiences. The formula for determining the moments of an object can also be used to find the moments for any other two sets of two points: for instance, if there is a force applied to an object at two different points, you can find the moments by multiplying the tangent at each point by the derivative of the force on the object at that particular point.
A mathematical formula for moments can be derived using the following relationship: The distance from a reference point A to a point B is equal to the tangential force acting on B when the angle between A and B is given. This equation can be solved for angles and the resulting values are moments. The formula for moments is very similar for torques. The only difference is the reference point, which may be a rotation about the axis of rotation or a fixed point.
The moment arms of a dynamic system are tangent lines connecting the source of force A to the location where the force is applied. The moments of an object are the product of the moments of the source of force A and the moments of the tangent line of that force A. The moments are then plotted against the tangent line to determine the moments of inertia. The concept of Momentum is used in aerodynamics as it describes the power or strength with which an aircraft moves with respect to its overall momentum.