مفردات TOEFL

planet outside our solar system

系外行星；太阳系外行星

interaction that can change motion or shape

力

part of structure transferring loads to ground

基础；建筑基础

motion under gravity without other significant forces

自由落体运动

number of repeated cycles per unit time

频率

contact force opposing relative sliding or its tendency

摩擦力；摩擦

large gravitationally bound system of stars and other matter

星系

large planet composed mainly of hydrogen and helium

气态巨行星

toothed machine part transmitting motion

齿轮

machine converting mechanical energy to electrical energy

发电机

gravitational interaction between physical bodies

引力；重力

operated by liquid pressure or flow

液压的；水力的

resistance to change in velocity

惯性

limit electric current between objects or regions

使绝缘；作绝缘处理

material strongly limiting electric charge movement

绝缘体；绝缘材料

energy associated with motion

动能

optical component redirecting light by refraction

透镜

rigid member turning about a pivot

杠杆

visible electromagnetic radiation

光；可见光

distance light travels in vacuum in one year

光年

energy emitted by a celestial object per unit time

光度；天体辐射功率

field describing magnetic influence in space

磁场

quantity measuring inertia of an object

质量

relating to machines or physical forces and motion

机械的；力学的

ratio of output force to input force

机械利益；机械增益

sum of kinetic and potential energy

机械能

energy transfer by force along displacement

机械功

mass times velocity in classical mechanics

动量

change of position relative to a reference

运动