Tech Bowl 8

Static Friction

A type of friction that occurs when there is no relative motion between the object and the surface (no sliding).

Kinetic Friction

A type of friction that occurs when there is relative motion (when the surface is sliding).

Coefficient of Friciton

Represents the nature of surfaces.

Law of Conservation of Energy

Energy can not just appear out of nowhere nor can it disappear in a closed system; it must always take on another form.

Work

The application of force over a distance and the resulting change in energy of the system that the force is acted on.

Total Mechanical Energy

The sum of an object's kinetic and potential energies.

Power

The rate at which work gets done, or energy gets transferred.

Impulse

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

Impulse-Momentum Theorem

Another way of writing Newton's Second Law. (Written J = change in momentum)

Momentum

A vector quantity given by p = mv

Uniform Circular Motion

When an objects speed around its path is constant.

Centripetal Acceleration

When the acceleration vector points toward the center of the circle. The thing that turns the velocity vector to keep the object traveling in a circle.

Newton's Law of Gravitation

Any two objects in the universe that exert and attractive force on each other - called the gravitiational force - whoes strength is proportional to the product of the object's masses and

Kinematics

The mathematical tools for describing motion in terms of displacement, velocity, and acceleration.

Potential Energy

The energy of an object or system has by virtue of its position of configuration.

Total Mechanical Energy

The sum of an objects kinetic and potential energies.

Law of Conservation of Total Energy

K(initial)+U(Initial) = K(final)+U(final)

Elastic Collision

A type of collision in which the objects bounce perfectly off each other in opposite directions. Kinetic Energy is conserved. Momentum is conserved.

Inelastic Collision

A type of collision in which the objects travel in the same direction after the collision. Kinetic Energy is lost. Momentum is conserved.

Perfectly Inelastic Collision

The objects stick together and travel in the same direction. Greatest kinetic energy is lost. Momentum is conserved.

Law of Conservation of Momentum

The momentum before equals the momentum after. total p (initial) = total p (final).

Uniform Circular Motion

The objects speed around its path (constant).

Centripetal Force

The force that produces centripetal acceleration. Pulls on object toward the center.

Universal Gravitational Constant

9.81, signified by the capital letter G.

Torque

The measure of a force's effectiveness at making an object spin or rotate.

Translational Equilibrium

Occurs when the sum of the forces acting on an object are zero.

Rotational Equilibrium

If the sum of the torques acting on an object is zero.

Static Equilibrium

State of equilibrium when an object is at rest.

Rotational Inertia

The tendency of an object in motion to rotate until its acted upon by an outside force.

Equilibrium Position

When a spring is neither stretched nor compressed it is said to be in it ___________ ____________.

Hooke's Law

F = -kx

Simple Harmonic Motion

Any vibrating system for which the restoring force is directly proportional to the negative of the displacement is said to exhibit _________________ _______________ ______________.

Amplitude

The maximum displacement from equilibrium.

Period (T)

The amount of time it takes to complete a cycle.

Frequency

The number of cycles that can be completed per unit time.

Simple Pendulum

Consists of a weight of mass attached to a string or a mass-less rod that swings, without friction, about the vertical equilibrium position.

Mechanical Wave

A disturbance transmitted by a medium from one point to another, without the medium its self being transported.

Crests

The points at which the rope has its maximum vertical displacement above the horizontal.

Troughs

The points at which the rope has its maximum vertical displacement below the horizontal.

Transverse Wave

A wave vibrating perpendicular to the direction in which it propagates (travels horizontally).

Superposition (Of Waves)

When two or more waves meet, the displacement at any point of the medium is equal to the algebraic sum of the displacements due to the individual waves.

Constructive Interference

When two waves has displacements of the same sign when they overlap, the combined wave will have a displacement of greater magnitude than either individual wave.

Destructive Interference

When two waves have opposite displacements and meet, the combined waveform will have a displacement of smaller magnitude than either individual wave.

Inphase

When two waves meet and the crest meets the crest and trough meets trough perfectly. These waves constructively interfere and the amplitude of the combined wave will be the sum of the individual amplitudes.

Out of Phase

When two waves meet and the crest of one meets the trough of the other and vice versa. These waves will destructively interfere completely and the amplitude of the combined wave will be the difference between the individual amplitudes.

Standing Wave

The wave oscillates vertically and remains fixed. The crests and troughs no longer travel down the length of the string.

Longitudinal Wave

A wave the travels and oscillates in the same direction. (i.e sound waves)

Intensity

The rate at which sound waves transmit energy, per unit area.