Biomechanics

Scalar Quantities

Physical quantities that have only magnitude, such as distance and speed.

Acceleration Calculation

Requires initial velocity, final velocity, change in velocity, and time.

Factors Affecting Air Time of Projectiles

The projection height influences the time a horizontally projected object stays in the air.

Pace

The quantity calculated as the inverse of speed.

Horizontal Component of Projectile Velocity

Remains constant throughout the flight when ignoring air resistance.

Distance vs. Displacement

Distance is the total movement in a straight line, while displacement is the shortest path between the initial and final position.

Acceleration Behavior

If acceleration is constant and positive, the velocity is increasing.

Elite Long Jumper Take-off Angles

They have take-off angles lower than 45° because higher take-off velocities are achieved at these angles.

Projectile Trajectory Influences

The shape of a projectile's trajectory is influenced by the angle of projection and air resistance.

Trajectory

The flight path of a projectile.

Angular Acceleration

The rate of change in angular velocity.

Radial Acceleration

The component of angular acceleration directed toward the center of curvature.

Radian

A unit of angular measure.

Angular Velocity

Measured in radians per second; W = q/t, describing the rate of change in angular position.

Angular Distance

A scalar quantity that measures the angle through which an object has rotated.

Right Hand Rule

A procedure to identify the direction of an angular motion vector.

Radius of Rotation

In the equation v = rw, r represents the radius of rotation.

Momentum

The quantity of motion an object possesses, dependent on mass and velocity.

Radial Acceleration Dependence

Directly affected by both tangential velocity and radius of rotation.

Momentum Determinants

The two variables that determine momentum are mass and velocity.

Non-time Dependent Mechanical Quantity

Potential energy does not depend on time.

Coefficient of Restitution

A measure of the elasticity of a ball against a specific surface.

Kinetic Energy

The energy an object possesses due to its motion.

Mechanical Power

A mechanical quantity present in explosive track and field events, indicating power output.

Unit of Mechanical Energy

Joules are the units used to measure mechanical energy.

Collision Direction Determinant

The relative moments of two bodies determine the direction of collective motion after a head-on collision.

Horizontal Force to Start Motion

The horizontal force required to start an object in motion must be greater than the coefficient of static friction.

Friction and Gloves

Wearing gloves increases friction between hands and a bat.

Projectile

A body in free fall subject only to gravity and air resistance.

Gravity

The force that attracts a body toward the center of the earth, or toward any other physical body having mass.

Air Resistance

The forces that oppose the motion of an object through air.

Apex

The highest point in the trajectory of a projectile.

Newton’s Law of Inertia

Also known as the conservation of momentum, emphasizing that an object will maintain its state of motion unless acted upon by an external force.

Clockwise Direction

In rotational motion, clockwise is considered the negative direction.

Elasticity Index Number

The number that measures restitution; relates to elasticity.