Question

17£®Ð¡Àî¼ÒÂò»Øһ̨ÐÂÐÍ¿ìËÙµçÈÈË®ºøÈçͼ¼×Ëùʾ£¬ÆäÄÚ²¿¹¤×÷µç·ÈçͼÒÒËùʾ£º´ËºøÔÚÉÕˮʱÊÇÔÚ¼ÓÈȵ¨Öд¢Ë®£¬ÓÉ¡°µçÈȹܡ±R₁¼ÓÈȹ¤×÷µÄ£ºµ±ºøÄÚË®ÉÕ¿ªÊ±£¬Æäοؿª¹ØS×Ô¶¯¶Ï¿ª£¬µçÈÈË®ºø´¦ÓÚ±£ÎÂ״̬£®µçÈÈË®ºøµÄÃúÅÆÉϱêÓÐÈçϱíÖУ¨Èç±íËùʾ£©Êý¾Ý£®Çó£º

ÐͺÅ	ÔÊÐíµÄ×î´ó×°Ë®ÖÊÁ¿	¼ÓÈÈʱµç·×ܹ¦ÂÊ	±£ÎÂʱµç·×ܹ¦ÂÊ	¶î¶¨µçѹ
1DE-102	2kg	2000W	50W	220V

£¨1£©µçÈÈË®ºø°Ñ×°ÓÐ2kg£¬20¡æµÄË®ÉÕ¿ª×îÉÙÐèÒªÏûºÄµçÄܶàÉÙ½¹¶ú£¿£¨Ò»±ê×¼´óÆøѹÏ£©£¨Ë®µÄ±ÈÈÈÈÝΪcË®=4.2¡Á10³J/kg•¡æ£©
£¨2£©½«´Ë×°ÓÐ2kg£¬20¡æµÄµçÈÈË®ºø½ÓÔÚ220Vµç·ÖÐʱ£¬Ð¡Àîʵ¼Ê²âÁ¿ÁËÆä¼ÓÈÈʱ¼äΪ8min£¬Ôò´ËµçÈÈË®ºøʵ¼ÊºÄµç¶àÉÙ½¹¶ú£¿
£¨3£©½«´ËµçÈÈË®ºø½ÓÔÚ220Vµç·ÖÐʱ£¬ÒªÊ¹µçÈÈË®ºøÂú×㱣ι¦ÂÊ£¬Í¼ÖÐR₀µÄµç×èӦȡ¶à´óÖµ£®

Answer 1

·ÖÎö £¨1£©Ë®ÎüÊÕµÄÈÈÁ¿¼´ÎªÖÁÉÙÏûºÄµÄµçÄÜ£¬¿ÉÒÔÀûÓù«Ê½Q_Îü=cm£¨t-t₀£©ÇóµÃ£»
£¨2£©ÀûÓÃW=PtÇó³öÏûºÄµÄµçÄÜ£»
£¨3£©ÓÉͼ¸ù¾ÝP=$\frac{{U}^{2}}{R}$ÖªS±ÕºÏΪ¼ÓÈÈ״̬£¬S¶Ï¿ªÎª±£ÎÂ״̬£¬¸ù¾Ýµç·ÌصãºÍR=$\frac{{U}^{2}}{P}$¼ÆËãµç×裮

½â´ð ½â£º
£¨1£©ÖÁÉÙÏûºÄµÄµçÄÜΪ£º
W=Q_Îü=cm£¨t-t₀£©=4.2¡Á10³J/£¨kg•¡æ£©¡Á2kg¡Á£¨100¡æ-20¡æ£©=6.72¡Á10⁵J£»
£¨2£©µçÈÈË®ºø½ÓÔÚ220Vµç·ÖÐÕý³£¹¤×÷£¬¼ÓÈÈʱ¼äΪ8minÏûºÄµçÄÜ£º
W=Pt=2000W¡Á8¡Á60s=9.6¡Á10⁵J£»
£¨3£©ÓÉͼµ±S±ÕºÏʱֻÓеçÈȹÜR₁Á¬Èëµç·ÖУ¬
ÓÉP=$\frac{{U}^{2}}{R}$¿ÉµÃR₁µÄµç×èΪ£º
R₁=$\frac{{U}^{2}}{{P}_{¼ÓÈÈ}}$=$\frac{£¨220V£©^{2}}{2000W}$=24.2¦¸£¬
µ±S¶Ï¿ªÊ±£¬Á½µç×è´®Áª£¬
ËùÒÔR₁+R₀=$\frac{{U}^{2}}{{P}_{±£ÎÂ}}$£¬
¼´£º24.2¦¸+R₀=$\frac{£¨220V£©^{2}}{50W}$
½âµÃ£ºR₀=943.8¦¸£®
´ð£º£¨1£©µçÈÈË®ºø°Ñ×°Ë®ÉÕ¿ª×îÉÙÐèÒªÏûºÄ6.72¡Á10⁵JµçÄÜ£»
£¨2£©Êµ¼Ê²âÁ¿ÁËÆä¼ÓÈÈʱ¼äΪ8min£¬Ôò´ËµçÈÈË®ºøʵ¼ÊºÄµç9.6¡Á10⁵J£»
£¨3£©ÒªÊ¹µçÈÈË®ºøÂú×㱣ι¦ÂÊ£¬R₀µÄµç×èӦȡ943.8¦¸£®

µãÆÀ ±¾ÌâÊǵçÈÈË®ºøÉÕË®µÄÎÊÌ⣬¿¼²éÁËÈÈÁ¿¼ÆËã¡¢µç¹¦¡¢µç¹¦ÂʼÆËãÒÔ¼°´®Áªµç·ÌصãµÈ£¬×ÛºÏÐÔÇ¿£¬ÕýÈ··ÖÎö¼ÓÈȺͱ£ÎÂ״̬Êǹؼü£®