sat物理的高频词汇有哪些

在sat物理部分的备考过程中，考生要掌握一些物理方面的必背高频词汇。下面就让本站小编给大家分享sat考试物理的`一些高频词汇相关知识吧，希望能对你有帮助!

Neutron

A neutrally charged particle that, along with protons, constitutes the nucleus of an atom.

Neutron number

The number, N, of neutrons in an atomic nucleus.

Newton

A unit of force: 1 N is equivalent to a 1 kg · m/s2.

Newton’s First Law

An object at rest remains at rest, unless acted upon by a net force. An object in motion remains in motion, unless acted upon by a net force.

Newton’s Law of Universal Gravitation

The force of gravity, F, between two particles of mass and , separated by a distance r, has a magnitude of , where G is the gravitational constant. The force is directed along the line joining the two particles.

Newton’s Second Law

F = ma. The net force, F, acting on an object causes the object to accelerate, a. The magnitude of the acceleration is directly proportional to the net force on the object and inversely　proportional to the mass, m, of the object.

Newton’s Third Law

To every action, there is an equal and opposite reaction. If an object A exerts a force on another object B, B will exert on A a force equal in magnitude and opposite in direction to the force exerted by A.

Node

The points on a standing wave where total destructive interference causes the medium to remain fixed at its equilibrium position.

Normal

The line perpendicular to a surface. There is only one normal for any given surface.

Normal force

The reaction force of the ground, a table, etc., when an object is placed upon it. The normal force is a direct consequence of Newton’s Third Law: when an object is placed on the ground, the ground pushes back with the same force that it is pushed upon. As a result, the net force of an object on the ground is zero, and the object does not move.

Nuclear fission

A nuclear reaction in which a high-energy neutron bombards a heavy, unstable atomic nucleus, causing it to split into two smaller nuclei, and releasing some neutrons and a vast amount of energy at the same time.

Nuclear fusion

A nuclear reaction that takes place only at very high temperatures. Two light atoms, often hydrogen, fuse together to form a larger single atom, releasing a vast amount of energy in the process.

Nucleus

The center of an atom, where the protons and neutrons reside. Electrons then orbit this nucleus.

Radian

A unit for measuring angles; also called a “rad.” 2π rad = 360o.

Radiation

Heat transfer via electromagnetic waves.

Radioactive decay

The process by which unstable nuclei spontaneously release particles and/or energy so as to come to a more stable arrangement. The most common forms of radioactive decay are alpha decay, beta decay, and gamma decay.

Radioactivity

An object is called radioactive if it undergoes radioactive decay.

Radius of curvature

With spherical mirrors, the radius of the sphere of which the mirror is a part.

Rarefaction

An area of high air pressure that acts as the wave trough for sound waves. The spacing between successive rarefactions is the wavelength of sound, and the number of successive areas of rarefaction that arrive at the ear per second is the frequency, or pitch, of the sound.

Real image

An image created by a mirror or lens in such a way that light does actually come from where the image appears to be. If you place a screen in front of a real image, the image will be projected onto the screen.

Reflect

A wave on a string that is tied to a pole at one end will reflect back toward its source, producing a wave that is the mirror-image of the original and which travels in the opposite direction.

Reflected ray

The ray of light that is reflected from a mirror or other reflecting surface.

Reflection

The phenomenon of light bouncing off a surface, such as a mirror.

Refracted ray

The ray of light that is refracted through a surface into a different medium.

Refraction

The bending of light as it passes from one medium to another. Light refracts toward the normal when going from a less dense medium into a denser medium and away from the normal when going from a denser medium into a less dense medium.

Restoring force

The force that causes simple harmonic motion. The restoring force is always directed toward an object’s equilibrium position.

Right-hand rule

A means of defining the direction of the cross product vector. To define the direction of the vector , position your right hand so that your fingers point in the direction of A, and then curl them around so that they point in the direction of B. The direction of your thumb shows the direction of the cross product vector.

Rigid body

An object that retains its overall shape, meaning that the particles that make up the rigid body stay in the same position relative to one another.

Rotational kinetic energy

The energy of a particle rotating around an axis.

Rotational motion

Occurs when every point in the rigid body moves in a circular path around a line called the axis of rotation.

Harmonic series

The series of standing waves supported by a string with both ends tied down. The first member of the series, called the fundamental, has two nodes at the ends and one anti-node in the middle. The higher harmonics are generated by placing an integral number of nodes at even intervals over the length of the string. The harmonic series is very important in music.

Heat

A transfer of thermal energy. We don’t speak about systems “having” heat, but about their “transferring” heat, much in the way that dynamical systems don’t “have” work, but rather “do” work.

Heat engine

A machine that operates by taking heat from a hot place, doing some work with that heat, and then exhausting the rest of the heat into a cool place. The internal combustion engine of a car is an example of a heat engine.

Heat transfer

A transfer of thermal energy from one system to another.

Hertz (Hz)

The units of frequency, defined as inverse-seconds (1 Hz = 1 s–1). “Hertz” can be used interchangeably with “cycles per second.”

Hooke’s Law

For an oscillating spring, the restoring force exerted by the spring is directly proportional to the displacement. That is, the more the spring is displaced, the stronger the force that will pull toward the equilibrium position. This law is expressed mathematically as F = –kx, where F is the restoring force and x is the displacement. The constant of proportionality, –k, is the spring constant.

Hypotenuse

The longest side of a right triangle, opposite to the right angle.