Temperature – a measure of the average kinetic energy

Temporal coherence – the maintaining of a constant phase difference between waves over time

Tensile strain – the fractional change in length produced by an applied force

Tensile stress – the ratio of the magnitude of an applied force to the cross-sectional area to which it is applied

Tension – a force along the length of an object (string, rope, wire, etc.)

Terminal potential difference – (TPD) the potential difference across terminals of a battery (see equation 18.12)

Terminal speed - the constant speed resulting from the sum of all upward forces being equal to the gravitational force (see Section 10.8)

Terminal velocity – the constant speed resulting when the sum of the forces reaches zero, usually because one of the forces is velocity dependent (see figure 10.23)

Tesla – the SI unit for the strength of a magnetic field

Thermal conductivity – property of a material indicating its ability to transfer heat

Thermal efficiency – ratio of the work done to the heat input (see equation 13.3)

Thermal equilibrium – objects are in thermal equilibrium if they are at the same temperature

Thermodynamic system – any collection of objects considered together

Thermodynamics– area of physics dealing with the relationship between heat and work

Thermometer – a device used to measure temperature

Thin lens – a lens whose thickness is small in comparison with its focal length

Thin-lens equation - algebraic expression relating the object distance, the image distance, and the focal length of the lens

Threshold energy – in a nuclear reactions, the lowest energy for an incoming particle for which a reaction will take place

Threshold frequency– the frequency of light below which ejection of photoelectrons will not occur, no matter how great the intensity of the incident light

Time dilation – an increase in the time interval between events measured by a moving observer (see equation 25.2)

Torque – the quantity measuring how effectively a force causes rotation

Total internal reflection – results when the angle of incidence (of light going from a more dense medium to a less dense medium) exceeds the critical angle and all the incident light is reflected back into the denser medium

Transformer – a device constructed of two adjacent multiturn coils of wire to increase or decrease an AC voltage without loss of power (see figure 20.7 and equation 20.6)

Translational kinetic energy - kinetic energy possessed by a particle m moving with speed v due to its translational motion in units of joules (see Section 6.4)

Transverse waves – a wave in which the disturbance (particles of the medium) making up the wave move at right angles to the direction of the propagation of the wave

Transverse wave pulse – a pulse in which the displacement (which makes up the pulse) is at right angles to the direction the wave pulse travels

Traveling wave – a wave or pulse that moves through space (or any medium) and does not set up a stationary vibrational pattern

Tunneling – (barrier penetration) the existence of a non-zero probability that a particle will appear outside a barrier that it cannot classically penetrate

Turbulent flow – fluid flow characterized by irregular, complex motion