T

Tail
In the graphical representation of vectors, the tail of the arrow is the blunt end (the end without a point).
Tangent
In a right triangle, the tangent of a given angle is the length of the side opposite the angle divided by the length of the side adjacent to the triangle.
Temperature
A measure of the average kinetic energy of the molecules in a system. Temperature is related to heat by the specific heat of a given substance.
Tension force
The force transmitted along a rope or cable.
Thermal energy
The energy of the molecules that make up an object. It is related to heat, which is the amount of energy transferred from one object to another object that is a different temperature.
Thermal equilibrium
Two materials are in thermal equilibrium if they are at the same temperature.
Third Law of Thermodynamics
An object cannot be cooled to absolute zero.
Threshold frequency
A property of a metal, the minimum frequency of electromagnetic radiation that is necessary to release photoelectrons from that metal.
Tip
In the graphical representation of vectors, the tip of the arrow is the pointy end.
Torque
The effect of force on rotational motion.
Total internal reflection
The phenomenon by which light traveling from a high n to a low n material will reflect from the optical interface if the incident angle is greater than the critical angle.
Transformer
A device made of two coils, which converts current of one voltage into current of another voltage. In a step-up transformer, the primary coil has fewer turns than the secondary, thus increasing the voltage. In a step-down transformer, the secondary coil has fewer turns than the primary, thus decreasing the voltage.
Translational kinetic energy
The energy of a particle moving in space. It is defined in s of a particle’s mass, m, and velocity, v, as (1/2)mv2.
Translational motion
The movement of a rigid body’s center of mass in space.
Transverse waves
Waves in which the medium moves in the direction perpendicular to the propagation of the wave. Waves on a stretched string, water waves, and electromagnetic waves are all examples of transverse waves.
Traveling waves
A wave with wave crests that propagate down the length of the medium, in contrast to stationary standing waves. The velocity at which a crest propagates is called the wave speed.
Trough
The points of maximum negative displacement along a wave. They are the opposite of wave crests.