'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 液态变气态是汽化,吸热。汽化是指物质从液态变为气态的相变过程。蒸发和沸腾是物...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 内能与热量 1.内能:物体内部所有分子做无规则运动的动能和分子势能的总和叫内能。...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 物态变化: (1)熔化:固液,吸热(冰雪融化) (2)凝固:液固,放热(水结冰) (3)汽化:液气...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 物态变化知识总结 1. 温度:是指物体的冷热程度。测量的工具是温度计, 温度计是根据...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 电和热 1、探究电流的热效应跟电阻大小的关系:铜丝与电阻丝串联,电流相同,相同时...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 人的可闻声范围是20Hz20kHz,低于20Hz的次声,人耳听不到。根据f=1/T,即T50ms,周期大于...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 声音的传播 1.声传播是通过介质来传播的。 2.回声是由于声音在传播过程中遇到障碍物...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 噪声的危害与控制 1.噪声: 从物理学角度来看,噪声是发声体做无规则振动产生的; 从...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 声音的产生需要的条件是振动。声音作为波的一种,频率和振幅就成了描述波的重要属...
'); (window.slotbydup=window.slotbydup || []).push({ id: '8096091', container: s, size: '580,90', display: 'inlay-fix' });})(); 声音的三个特性是:音调、响度、音色。(音调与物体的振动频率有关;响度与物体的振幅...