Liftoff to Learning: Toys in Space 2

Glossary of Science Terms,
Principles and Mathematical
Equations

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G-Force - The ratio produced when the force felt by an object is divided by the weight of that object when motionless on the Earth's surface.

Gravitational Potential Energy - This is the energy possessed by an object by virtue of its position relative to the Earth or any large mass.

Gravity- The attraction of all objects to one another due to their mass.

Gyroscopic Stability - This term describes the resistance of a spinning object to any torque that would change the orientation of the object's spin axis.

Heat Energy - This is the energy associated with the vibration of atoms and molecules.

Inertia - This is the property by which an object tends to resist any change in its motion.

Kinetic Energy - This is the energy possessed by an object because of its motion.

Law of Universal Gravitation - All particles exert a gravitational force of attraction upon each other. The magnitude of the force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

(Note: G is a constant, r = distance between the center of masses for the two objects.)

Longitudinal Wave - A wave which vibrates back and forth in the direction of the wave's motion. (Also called a compression wave)

Magnetism - This is a property of certain objects in which there is an attraction to unlike poles of other objects. Its origin lies in the orientation of atoms within the object. The strength of the magnetic force varies inversely with the square of the distance between the magnets. The magnetic force drops off very quickly with distance.

Mass - This is the amount of matter an object contains.

Microgravity - An environment, produced by freefall, that alters the local effects of gravity and makes objects seem weightless.

Moment of Inertia - The moment of inertia for a spinning body depends on the mass distribution relative to the axis of rotation. The moment of inertia equals the sum of the mass times the square of the distance from the axis of spin for each particle in the body. The moment of inertia is greater for spinning objects with their mass distributed farther from the axis of rotation. Gyroscopes and tops are designed on this principle.

Momentum - This is the product of an object's mass times its velocity. Momentum is a conserved quantity within a closed system.

Momentum = mass x velocity

Greg Harbaugh slam dunks a basket.	Mission specialist Mario Runco tries the Klackers.

Newton's Laws of Motion - Sir Isaac Newton first formulated these three basic laws of motion:

Newton's First Law of Motion - An object continues in its initial state of rest or motion with uniform velocity unless acted on by an unbalanced external force. This is also called the Law of Inertia or the Inertia Principle.

Newton's Second Law of Motion - The acceleration of an object is inversely proportional to its mass and directly proportional to the resultant external force acting on it.

Force = mass x acceleration

Newton's Second Law for Rotation - The torque of a spinning object is equal to the object's moment of inertia times its angular acceleration. The fact that a torque is required to change a spinning gyroscope's angular velocity is called gyroscopic stability.

Newton's Third Law of Motion - Forces always occur in pairs. If object A exerts a force on object B, an equal but opposite force is exerted by object B on object A. Application: objects move forward by pushing backward on a surface or on a fluid.

Node - This is a point in a standing wave where no motion occurs (zero amplitude).

Parabola - One possible path of an object falling freely in a gravity field. A tossed ball follows a parabolic arc.

Photon - This is a packet of radiant energy.

Potential Energy - This is the energy required to place an object in a position. This energy is stored in the object until the object moves. It is then converted into another form of energy, such as kinetic or thermal.

Precession -This is the wobbling of a spinning object.

Rarefaction - This is the part of a longitudinal wave where the density is lower than the surrounding medium.

Reaction Force - This is the force exerted by an object experiencing an action force. The reaction force is equal to the action force but in the opposite direction.

Surface Tension - This is the strength of the boundary film at the surface of a liquid.

Speed - This is the rate of change of an object's position with time.

Torsional Wave - This is the wave caused by twisting a coiled spring.

Transverse Wave - This is the wave in which vibrations are to the left and right as the wave moves forward.

Trough - This is a wave valley.

Velocity - This is the speed and direction of an object's motion.

Wave Motion - In a longitudinal wave, the vibration of the medium is along the same direction as the motion of the wave. A longitudinal wave is also called a compression wave. In a transverse wave, the vibration of the medium is perpendicular to the motion of the wave. A vibration caused by twisting the coiled spring is called a torsional wave.

A standing wave has places where the wave appears to stand still. Locations where the waves interfere to produce no motion are called nodes.

The frequency of a wave is the number of vibrations per unit time. The wavelength is the distance between two wave crests. The wave's speed of propagation is equal to the frequency times the wavelength.

Wavelength - This is the distance between two identical points in a wave (e.g. from crest to crest).

Weight -This is the magnitude of a gravitational pull.

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