ÌâÄ¿ÄÚÈÝ
£¨2013?Î人ģÄ⣩ÈçͼÊÇСÃ÷ͬѧ²âÁ¿Ð±Ãæ»úеЧÂʵÄʵÑé×°Öã®ÊµÑéʱÓõ¯»É²âÁ¦¼ÆÀ×ÅÖØΪ8NµÄľ¿éÑØбÃæÏòÉÏ×öÔÈËÙÖ±ÏßÔ˶¯£¬µ¯»É²âÁ¦¼ÆµÄʾÊýÈçͼËùʾ£®ÔÚÕâ´ÎʵÑéÖУ¬µ¯»É²âÁ¦¼ÆÑØбÃæµÄÀÁ¦Îª
4.8N
4.8N
£¬Ð±ÃæµÄ»úеЧÂÊΪ62.5%
62.5%
£¬Ä¾¿éºÍбÃæ¼äµÄĦ²ÁÁ¦Îª1.8N
1.8N
£®ÈôҪ̽¾¿Ð±ÃæµÄ»úеЧÂʺÍÎïÌåÖØÁ¦µÄ¹Øϵ£¬Ó¦¿ØÖÆбÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È
бÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È
±£³Ö²»±ä£®·ÖÎö£º£¨1£©¸ù¾Ýµ¯»É²âÁ¦¼ÆµÄ·Ö¶ÈÖµ¶Á³öÀÁ¦µÄ´óС£¬¸ù¾ÝW=FsÇó³ö×ܹ¦£¬ÀûÓÃÏàËÆÈý½ÇÐζÔÓ¦±ä³É±ÈÀýÇó³öÎïÌåÉÏÉýµÄ¸ß¶È£¬ÔÙ¸ù¾ÝW=GhÇó³öÓÐÓù¦£¬ÀûÓÃЧÂʹ«Ê½Çó³öбÃæµÄ»úеЧÂÊ£®
£¨2£©Ä¦²ÁÁ¦×öµÄ¹¦¼´Îª¶îÍ⹦£¬¸ù¾ÝW=FsÇó³öĦ²ÁÁ¦µÄ´óС£®
£¨3£©Ó°ÏìбÃæ»úеЧÂʵÄÒòËØÓÐÎï¿éÖØÁ¦¡¢Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È£¬¸ù¾Ý¿ØÖƱäÁ¿·¨¿ÉÖª£¬ÔÚÑо¿»úеЧÂʺÍijһÒòËعØϵʱ£¬Òª¿ØÖÆÆäËûÁ½¸öÒòËر£³ÖÒ»¶¨£®
£¨2£©Ä¦²ÁÁ¦×öµÄ¹¦¼´Îª¶îÍ⹦£¬¸ù¾ÝW=FsÇó³öĦ²ÁÁ¦µÄ´óС£®
£¨3£©Ó°ÏìбÃæ»úеЧÂʵÄÒòËØÓÐÎï¿éÖØÁ¦¡¢Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È£¬¸ù¾Ý¿ØÖƱäÁ¿·¨¿ÉÖª£¬ÔÚÑо¿»úеЧÂʺÍijһÒòËعØϵʱ£¬Òª¿ØÖÆÆäËûÁ½¸öÒòËر£³ÖÒ»¶¨£®
½â´ð£º½â£º£¨1£©µ¯»É²âÁ¦¼ÆµÄ·Ö¶ÈֵΪ0.2N£¬ËùÒÔÀÁ¦µÄ´óСΪ4.8N£¬
ÀÁ¦×öµÄ×ܹ¦W×Ü=Fs=4.8N¡Á£¨0.64m+0.08m£©=3.456J£¬
Òò¡÷ABC¡×¡÷ADE£¬ÈçͼËùʾ£º
ËùÒÔÎïÌåÉÏÉýµÄ¸ß¶Èh=
=
=27cm=0.27m£¬
ÓÐÓù¦WÓÐ=Gh=8N¡Á0.27m=2.16J£¬
бÃæµÄ»úеЧÂʦÇ=
=
=62.5%£®
£¨2£©Ä¦²ÁÁ¦×öµÄ¹¦W¶î=W×Ü-WÓÐ=3.456J-2.16J=1.296J£¬
Ħ²ÁÁ¦f=
=
=1.8N£®
£¨3£©Ð±Ãæ»úеЧÂÊÓëÎï¿éÖØÁ¦¡¢Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶ÈÓйأ¬ÈôҪ̽¾¿Ð±ÃæµÄ»úеЧÂʺÍÎïÌåÖØÁ¦µÄ¹Øϵ£¬Ó¦¿ØÖÆбÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È±£³Ö²»±ä£®
¹Ê´ð°¸Îª£º4.8N£»62.5%£»1.8N£»Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È£®
ÀÁ¦×öµÄ×ܹ¦W×Ü=Fs=4.8N¡Á£¨0.64m+0.08m£©=3.456J£¬
Òò¡÷ABC¡×¡÷ADE£¬ÈçͼËùʾ£º
ËùÒÔÎïÌåÉÏÉýµÄ¸ß¶Èh=
AB¡ÁDE |
AD |
72cm¡Á30cm |
80cm |
ÓÐÓù¦WÓÐ=Gh=8N¡Á0.27m=2.16J£¬
бÃæµÄ»úеЧÂʦÇ=
WÓÐ |
W×Ü |
2.16J |
3.456J |
£¨2£©Ä¦²ÁÁ¦×öµÄ¹¦W¶î=W×Ü-WÓÐ=3.456J-2.16J=1.296J£¬
Ħ²ÁÁ¦f=
W¶î |
s |
1.296J |
0.64m+0.08m |
£¨3£©Ð±Ãæ»úеЧÂÊÓëÎï¿éÖØÁ¦¡¢Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶ÈÓйأ¬ÈôҪ̽¾¿Ð±ÃæµÄ»úеЧÂʺÍÎïÌåÖØÁ¦µÄ¹Øϵ£¬Ó¦¿ØÖÆбÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È±£³Ö²»±ä£®
¹Ê´ð°¸Îª£º4.8N£»62.5%£»1.8N£»Ð±ÃæÇãб³Ì¶ÈºÍбÃæ´Ö²Ú³Ì¶È£®
µãÆÀ£º±¾Ì⿼²éÁ˹¦ºÍ»úеЧÂÊ¡¢Ä¦²ÁÁ¦µÄ¼ÆËãÒÔ¼°µ¯»É²âÁ¦¼ÆµÄ¶ÁÊý£¬¹Ø¼üÊÇÖªµÀÓ°ÏìбÃæ»úеЧÂʵÄÒòËغͿØÖƱäÁ¿·¨µÄÓ¦Óã¬ÄѵãÊǸù¾ÝÏàËÆÈý½ÇÐεóöÎïÌåÉÏÉýµÄ¸ß¶È£¬»¹Òª×¢ÒâÎïÌåÒƶ¯¾àÀëµÄ¼ÆË㣬ÕâÒ²ÊÇѧÉúÈÝÒ׳ö´íµÄµØ·½£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿