Untitled Flashcard Set

lever

A rigid bar that rotates about a fixed point (fulcrum) to move a load using an applied effort.

effort

The force applied to a lever to move a load.

load (resistance)

The force or weight that the lever is designed to move.

fulcrum

The fixed pivot point about which a lever rotates.

first-class lever

A lever in which the fulcrum lies between the effort and the load.

second-class lever

A lever in which the load lies between the fulcrum and the effort.

third-class lever

A lever in which the effort lies between the fulcrum and the load.

mechanical advantage (MA)

The ratio of the effort arm length to the load arm length.

effort arm

The distance between the fulcrum and the point where the effort is applied.

load arm (resistance arm)

The distance between the fulcrum and the load.

internal lever

A lever system formed by bones, joints, and muscles within the human body.

external lever

A lever outside the body used to enhance movement or performance.

force

A push or pull that can change an object’s motion or shape.

resultant motion

The overall movement of an object resulting from the combination of all forces acting on it.

resultant force

The single force that has the same effect as all forces acting together.

linear motion

Motion along a straight line.

curvilinear motion

Motion along a curved path.

angular motion

Rotational motion about an axis.

general motion

A combination of linear and angular motion.

centre of mass (CoM)

The point at which the mass and weight of an object are balanced in all directions.

base of support (BoS)

The area beneath an object that supports its weight.

line of gravity

An imaginary vertical line passing through the centre of mass toward the base of support.

stability

The ability to maintain equilibrium by keeping the centre of mass within the base of support.

eccentric force

A force applied at a distance from the centre of mass that causes rotation.

moment of inertia

A measure of an object’s resistance to rotational motion.

angular velocity

The rate at which an object rotates about an axis.

angular momentum

The product of angular velocity and moment of inertia.

conservation of angular momentum

The principle that angular momentum remains constant unless acted upon by an external force.

impulse (linear)

The product of force and the time for which it acts.

principle of impulse direction

The direction of an impulse determines the direction of the change in momentum.

summation of joint forces

The combination of forces produced at joints to create movement.