SAT2物理常用术语词汇（P）

　　为了方便广大考生更好的复习，小编综合整理了SAT2物理常用术语词汇，以供各位考生考试复习参考,希望对考生复习有所帮助。>>免费申请出国留学<<

　　Pascals

　　The unit for measuring pressure. One Pascal is equal to one Newton per meter squared, 1 Pa = 1 N/m2.

　　Pendulum

　　A pendulum consists of a bob connected to a rod or rope. At small angles, a pendulum’s motion approximates simple harmonic motion as it swings back and forth without friction.

　　Period

　　The time it takes a system to pass through one cycle of its repetitive motion. The period, T, is the inverse of the motion’s frequency, f = 1/T.

　　Phase

　　Two oscillators that have the same frequency and amplitude, but reach their maximum displacements at different times, are said to have different phases. Similarly, two waves are in phase if their crests and troughs line up exactly, and they are out of phase if the crests of one wave line up with the troughs of the other.

　　Phase change

　　When a solid, liquid, or gas changes into another phase of matter.

　　Photoelectric fect

　　When electromagnetic radiation shines upon a metal, the surface of the metal releases energized electrons. The way in which these electrons are released contradicts classical theories of electromagnetic radiation and supports the quantum view according to which electromagnetic waves are treated as particles.

　　Photoelectron

　　The name of an electron released from the surface of a metal due to the photoelectric fect.

　　Photon

　　A small particle-like bundle of electromagnetic radiation.

　　Pitch

　　Another word for the frequency of a sound wave.

　　Planck’s constant

　　A constant, J · s, which is usul in quantum physics. A second constant associated with Planck’s constant is .

　　Polarization

　　A process that aligns a wave of light to oscillate in one dimension rather than two.

　　Potential energy

　　Energy associated with an object’s position in space, or configuration in relation to other objects. This is a latent form of energy, where the amount of potential energy rlects the amount of energy that potentially could be released as kinetic energy or energy of some other form.

　　Power

　　Dined as the rate at which work is done, or the rate at which energy is transformed. P is measured in joules per second (J/s), or watts (W).

　　Pressure

　　A measure of force per unit area. Pressure is measured in N/m2 or Pa.

　　Principal axis

　　The straight line that runs through the focal point and the vertex of a mirror or lens.

　　Proton

　　A positively charged particle that, along with the neutron, occupies the nucleus of the atom.

　　Pulley

　　A pulley is a simple machine that consists of a rope that slides around a disk or block.

　　小编提醒：单词的记忆要靠长期的坚持，考生们一定要持之以恒，每天都拿出来看一看背一背，让这些词汇在大脑中形成长期记忆，这样就不会轻易地忘记背过的词汇了。