Question

13£®Í¼¼×ËùʾÊÇÉú»îÖг£¼ûµÄ×Ô¶¯¼ÓÈÈ¡¢±£ÎµĵçË®ºø£¬Í¼ÒÒËùʾΪµçË®ºøµÄµç·ͼ£¬ÆäÖÐR₀ÊǵçÈÈË®ºøÖеĵçÈȹܣ¬RÊÇÓëµçÈÈË®ºøµÄµçÈȹܴ®ÁªµÄµç×裬SÊÇÒ»¸ö×Ô¶¯Çл»µÄοؿª¹Ø£¬´ËÈÈË®ºøÊÇÔÚÈȵ¨Öд¢Ë®£¬ÓɵçÈȹܼÓÈȹ¤×÷µÄ£¬ËüµÄÃúÅÆÈçÏÂ±í£¬Çó£º[c_Ë®=4.2¡Á10³J/£¨kg•¡æ£©]

¶î¶¨µçѹ	220V
ƵÂÊ	50Hz
ÈÝ»ý	6L
¼ÓÈȹ¦ÂÊ	1100W
±£Î¹¦ÂÊ	44W

£¨1£©Çë¸ù¾Ýµç·ͼÅжϣºµ±Î¿ؿª¹Ø±ÕºÏ»¹ÊǶϿªÊ±£¬µçË®ºø´¦ÓÚ¼ÓÈÈ״̬£¬ËµÃ÷ÀíÓÉ£»
£¨2£©°´ÃúÅÆÉÏËù±êµçË®ºøµÄÊý¾Ý£¬¼ÆËãR₀ºÍRµÄ×èÖµ·Ö±ðÊǶàÉÙ£»
£¨3£©µ±Ëü´¦ÓÚ¼ÓÈÈ״̬ʱ£¬Èç¹ûÏûºÄµÄµçÄÜÈ«²¿ÓÃÀ´¼ÓÈÈË®£¬Ê¹Èȵ¨ÖÐ2kg¡¢20¡æµÄË®¼ÓÈȵ½·ÐÌÚÖÁÉÙÐèÒª¶àÉÙʱ¼ä£®£¨ÆøѹΪ1±ê×¼´óÆøѹ£©

Answer 1

·ÖÎö £¨1£©µçË®ºøµÄ¼ÓÈȹ¦ÂÊ´óÓÚ±£Î¹¦ÂÊ£¬µçÔ´µçѹһ¶¨£¬¿ª¹ØÊÇÄÄÖÖ״̬¶ÔÓ¦¼ÓÈȹ¦ÂÊ£¬Óù«Ê½P=$\frac{{{U}^{2}}^{\;}}{R}$·ÖÎö£»
£¨2£©ÒÑÖªµçÈȺøµÄ¶î¶¨µçѹºÍ¼ÓÈȹ¦ÂÊ£¬ÀûÓù«Ê½R=$\frac{{U}^{2}}{P}$µÃµ½R₀µÄ×èÖµ£»ÒÑÖª±£Î¹¦ÂʺͶµçѹ£¬¿ÉÒԵõ½´®Áªµç·µÄ×ܵç×裬ÒÑÖª×ܵç×èºÍR₀µÄ×èÖµ£¬Á½ÕßÖ®²îÊÇRµÄ×èÖµ£»
£¨3£©ÒÑ֪ˮµÄ±ÈÈÈÈÝ¡¢ÖÊÁ¿¡¢³õζȺÍĩζȣ¬¸ù¾ÝQ_Îü=cm£¨t-t₀£©Çó³öË®ÎüÊÕµÄÈÈÁ¿£¬Ò²¾ÍÊǵçÈȺøÏûºÄµÄµçÄÜ£¬¸ù¾Ýt=$\frac{W}{P}$Çó³öÐèÒªµÄ¼ÓÈÈʱ¼ä£®

½â´ð ½â£º£¨1£©Óɵç·ͼ֪£º
µ±Î¿ؿª¹Ø±ÕºÏʱ£¬µç·ΪR₀µÄ¼òµ¥µç·£¬´ËʱÏûºÄµÄ¹¦ÂÊΪP₁=$\frac{{{U}^{2}}^{\;}}{{R}_{0}}$£»
µ±Î¿ؿª¹Ø¶Ï¿ªÊ±£¬µç×èRºÍR₀´®Áª£¬´ËʱÏûºÄµÄ¹¦ÂÊΪP₂=$\frac{{{U}^{2}}^{\;}}{R+{R}_{0}}$£¬
ÒòUÒ»¶¨£¬R+R₀£¾R£¬
ËùÒÔ£¬P₁£¾P₂£¬¼´Î¿ؿª¹Ø±ÕºÏʱ£¬µçË®ºø´¦ÓÚ¼ÓÈÈ״̬£»
£¨2£©ÓÉP=$\frac{{{U}^{2}}^{\;}}{R}$¿ÉÖª£¬µç×èR₀µÄ×èÖµ£º
R₀=$\frac{{U}^{2}}{{P}_{¼Ó}}$=$\frac{£¨220V£©^{2}}{1100W}$=44¦¸£¬
±£ÎÂ״̬ϵĵç·×ܵç×裺
R_´®=$\frac{{U}^{2}}{{P}_{±£}}$=$\frac{£¨220V£©^{2}}{44W}$=1100¦¸£¬
Òò´®Áªµç·ÖÐ×ܵç×èµÈÓÚ¸÷·Öµç×èÖ®ºÍ£¬
ËùÒÔ£¬µç×èRµÄ×èÖµ£º
R=R_´®-R₀=1100¦¸-44¦¸=1056¦¸£»
£¨3£©1±ê×¼´óÆøѹÏÂË®µÄ·ÐµãÊÇ100¡æ£¬ÔòË®ÎüÊÕµÄÈÈÁ¿£º
Q_Îü=cm£¨t-t₀£©=4.2¡Á10³J/£¨kg•¡æ£©¡Á2kg¡Á£¨100¡æ-20¡æ£©=6.72¡Á10⁵J£¬
ÒòÏûºÄµÄµçÄÜÈ«²¿ÓÃÀ´¼ÓÈÈË®£¬
ÓÉP=$\frac{W}{t}$=$\frac{{Q}_{Îü}}{t}$¿ÉµÃ£¬µçÈȺøµÄ¼ÓÈÈʱ¼ä£º
t¡ä=$\frac{{Q}_{Îü}}{{P}_{¼Ó}}$=$\frac{6.72¡Á1{0}^{5}J}{1100W}$¡Ö610.9s£®
´ð£º£¨1£©Î¿ؿª¹Ø±ÕºÏʱ£¬µçË®ºø´¦ÓÚ¼ÓÈÈ״̬£»Ô­ÒòÊÇοؿª¹Ø±ÕºÏʱ£¬µç·ÖеÄ×ܵç×è×îС£¬ÓÉP=$\frac{{U}^{2}}{R}$¿ÉÖªµçË®ºøµÄ¹¦ÂÊ×î´ó£»
£¨2£©µç×èR₀µÄ×èֵΪ44¦¸£»µç×èRµÄ×èֵΪ1056¦¸£»
£¨3£©µçÈȺøµÄ¼ÓÈÈʱ¼äΪ610.9s£®

µãÆÀ ±¾Ì⿼²éÁ˵繦ºÍÈÈÁ¿µÄ×ۺϼÆË㣬Éæ¼°µ½µçË®ºø¼ÓÈÈ״̬µÄÅжϡ¢µç¹¦Âʹ«Ê½¡¢µç¹¦¹«Ê½¡¢ÎüÈȹ«Ê½¡¢Ð§Âʹ«Ê½µÄÓ¦Óã¬Òª×¢Òâ1±ê×¼´óÆøѹÏÂË®µÄ·ÐµãÊÇ100¡æ£®