Question

19£®ÎªÁË̽¾¿¸¡Á¦µÄ´óСÓëʲôÒòËØÓйأ¬Ð¡Íõͬѧ°´ÕÕ¢Ù¡¢¢Ú¡¢¢Û¡¢¢Ü¡¢¢ÝµÄ˳Ðò×öÁËÈçͼËùʾµÄʵÑ飮
£¨1£©Í¼¢ÚÖÐÎïÌåÊܵ½µÄ¸¡Á¦´óСΪ0.4N£®
£¨2£©´Óͼ¢Ù¢Ú¢Û¿ÉÒԵóö£º¸¡Á¦µÄ´óСÓëÅÅ¿ªÒºÌåµÄÌå»ýÓйأ®
£¨3£©´Óͼ¢Ù¢Û¢Ü¿ÉÒԵóö£º¸¡Á¦µÄ´óСÓë½þûµÄÉî¶ÈÎ޹أ®
£¨4£©¸¡Á¦µÄ´óСÊÇ·ñÓëÒºÌåÃܶÈÓйØÄØ£¿Ð¡ÍõÔÙÈ¡Ò»ÉÕ±­£¬µ¹ÈëÊÊÁ¿µÄijҺÌ壬µ±ÎïÌåÍêÈ«½þÈë¸ÃÒºÌåÖÐʱ£¬µ¯»É²âÁ¦¼ÆµÄʾÊýÈçͼ¢ÝËùʾ£¬ËµÃ÷¸¡Á¦µÄ´óСÓëÒºÌåµÄÃܶÈÓйأ®¸ÃÖÖÒºÌåµÄÃܶÈΪ0.8¡Á10³kg/m³£®

Answer 1

·ÖÎö £¨1£©£¨2£©£¨3£©ÔÚ¡°Ì½¾¿¸¡Á¦´óСÓëʲôÒòËØÓйء±µÄʵÑéÖУ¬¸¡Á¦µÄ´óСÊÇͨ¹ýµ¯»É²âÁ¦¼ÆµÄʾÊý±ä»¯Çó³öÀ´µÄ£¬¹Û²ìʱӦÖصã¹Û²ìÎïÌå½þÈëÇé¿ö¶Ôµ¯»É²âÁ¦¼ÆʾÊýµÄÓ°Ï죬²¢¾Ý´Ë·ÖÎö½áÂÛ£®Í¬Ê±£¬»¹Í¨¹ýÕâһʵÑ飬¿¼²éÁËÒºÌåѹǿÓëÉî¶ÈµÄ¹Øϵ£®
£¨4£©¸ù¾Ý³ÆÖØ·¨¿ÉÖªÎïÌåÔÚË®Öеĸ¡Á¦£¬Çó³öÌå»ý£¬Çó³öÑÎË®ÖÐÊܵ½µÄ¸¡Á¦£¬¸ù¾ÝF_¸¡=¦Ñ_Ë®gV_ÅÅÇó³öÑÎË®µÄÃܶȣ®

½â´ð ½â£º£¨1£©Í¼¢ÚÖÐÎïÌåÊܵ½µÄ¸¡Á¦=4N-3.6N=0.4N£»
£¨2£©¹Û²ìͼ¢Ù¢Ú¢Û¿ÉÒÔ¿´³ö£¬ÎïÌåÅÅ¿ªµÄˮԽ¶à£¬µ¯»É²âÁ¦¼ÆµÄʾÊýԽС£¬Òò´ËµÃ³ö£¬¸¡Á¦µÄ´óСÓëÅÅ¿ªÒºÌåµÄÌå»ýÓйأ»
£¨3£©¹Û²ìͼ¢Ù¢Û¢Ü¿ÉÒÔ¿´³ö£¬µ±ÎïÌåÍêÈ«½þûºó£¬Éî¶ÈÔö¼Ó£¬µ¯»É²âÁ¦¼ÆµÄʾÊý²»±ä£¬Òò´ËµÃ³ö£¬¸¡Á¦µÄ´óСÓë½þûµÄÉî¶ÈÎ޹أ»
£¨4£©ÓÉͼ¼×¡¢±û¿ÉÖª£ºÎïÌåAÔÚË®ÖÐÊܵ½µÄ¸¡Á¦F_¸¡=G-F₂=4N-3N=1N£¬
ÓÉF_¸¡=¦Ñ_Ë®gV_ÅŵãºÎïÌåµÄÌå»ýV=V_ÅÅ=$\frac{{F}_{¸¡}}{{¦Ñ}_{Ë®}g}$=$\frac{1N}{1.0¡Á1{0}^{3}g/{m}^{3}¡Á10N/kg}$=¡Á10^-4m³£»
ÓÉͼ¼×¡¢¶¡¿ÉÖª£ºÎïÌåAÔÚÑÎË®ÖÐÊܵ½µÄ¸¡Á¦F_¸¡¡ä=G-F₃=4N-3.2N=0.8N£¬
ÓÉF_¸¡=¦Ñ_ÑÎË®gV_Åŵãº
¦Ñ_ÑÎË®=$\frac{{F'}_{¸¡}}{g{V}_{ÅÅ}}$=$\frac{0.8N}{10N/kg¡Á4¡Á1{0}^{-4}{m}^{3}}$=0.8¡Á10³kg/m³£®
¹Ê´ð°¸Îª£º£¨1£©0.4£»£¨2£©ÅÅ¿ªÒºÌåµÄÌå»ý£»£¨3£©½þûµÄÉî¶È£»£¨4£©ÒºÌåµÄÃܶȣ»0.8¡Á10³£®

µãÆÀ ±¾Ì⿼²éÁËʵÑéÏÖÏó·ÖÎö£¬Ó¦ÓÿØÖƱäÁ¿·¨·ÖÎöͼʾʵÑéÏÖÏó¼´¿ÉÕýÈ·½âÌ⣬ӦÓÿØÖƱäÁ¿·¨ÊÇÕýÈ·½âÌâµÄ¹Ø¼ü£®