Question

15£®¿ÕÆøÄÜÈÈË®Æ÷ÊÇͨ¹ýÎüÊÕ¿ÕÆøÖеÄÈÈÁ¿À´ÖÆÔìÈÈË®µÄ¡°ÈÈÁ¿°áÔË¡±×°Öã®Æ乤×÷Ô­ÀíÊÇ£º¿ÕÆøÄÜÈÈË®Æ÷ÔÚ¹¤×÷ʱ£¬´Ó¿ÕÆøÖÐÎüÊÕµÄÈÈÁ¿ÎªQ£¬ÏûºÄµÄµçÄÜΪW£¬Í¨¹ýÈȽ»»»Ê¹Ë®ÎüÊÕµÄÈÈÁ¿ÎªQ_Îü£¬¼´Q_Îü=Q+W£¬ÒÑ֪ijÐͺŵĿÕÆøÄÜÈÈË®Æ÷µç¹¦ÂÊΪ1800W£¬¹¤×÷ʱÏûºÄµÄµçÄÜWÊÇË®ÎüÊÕÈÈÁ¿Q_ÎüµÄËÄ·ÖÖ®Ò»£¬µ±ÓôËÈÈË®Æ÷½«150kgµÄË®´Ó15¡æ¼ÓÈȵ½55¡æʱ£®ÒÑÖª£ºË®µÄ±ÈÈÈÈÝΪ4.2¡Á10³J/£¨kg•¡æ£©£®Çó£º
£¨1£©Ë®ÎüÊÕµÄÈÈÁ¿£»
£¨2£©¿ÕÆøÄÜÈÈË®Æ÷Íê³ÉÉÏÊö¼ÓÈȹý³ÌËùÓõÄʱ¼ä£®

Answer 1

·ÖÎö £¨1£©ÖªµÀË®µÄÖÊÁ¿¡¢³õκÍĩΣ¬¸ù¾Ý¹«Ê½Q=cm£¨t-t₀£©Çó³öË®ÎüÊÕµÄÈÈÁ¿£»
£¨2£©ÒÑÖª¹¤×÷ʱÏûºÄµÄµçÄÜWÊÇË®ÎüÊÕÈÈÁ¿Q_ÎüµÄËÄ·ÖÖ®Ò»£¬ÓÖÖªµÀµç¹¦ÂÊ£¬¸ù¾Ý¹«Ê½P=$\frac{W}{t}$Çó³ö¼ÓÈÈʱ¼ä£®

½â´ð ½â£º
£¨1£©Ë®ÎüÊÕµÄÈÈÁ¿£º
Q_Îü=cm£¨t-t₀£©=4.2¡Á10³J/£¨kg•¡æ£©¡Á150kg¡Á£¨55¡æ-15¡æ£©=2.52¡Á10⁷J£»
£¨2£©¿ÕÆøÄÜÈÈË®Æ÷Íê³É¼ÓÈȹý³ÌÏûºÄµÄµçÄÜW=$\frac{Q}{4}$=$\frac{2.52¡Á1{0}^{7}J}{4}$=6.3¡Á10⁶J£»
ÓÉP=$\frac{W}{t}$¿ÉµÃ£¬ÉÏÊö¼ÓÈȹý³ÌËùÓõÄʱ¼ät=$\frac{W}{P}$=$\frac{6.3¡Á1{0}^{6}J}{1800W}$=3.5¡Á10³s£®
´ð£º£¨1£©Ë®ÎüÊÕµÄÈÈÁ¿Îª2.52¡Á10⁷J£»
£¨2£©¿ÕÆøÄÜÈÈË®Æ÷Íê³ÉÉÏÊö¼ÓÈȹý³ÌËùÓõÄʱ¼äΪ3.5¡Á10³s£®

µãÆÀ ¿ÕÆøÄÜÈÈË®Æ÷ÊôÓÚвúÆ·£¬Õë¶ÔвúÆ·£¬ÖØ´óʼþÉè¼ÆÎïÀíÎÊÌ⣬¶¼ÊÇÖп¼µÄÈȵ㣬һ¶¨Òª¹Ø×¢£®