Question

5£®Ä³Í¬Ñ§ÀûÓÃƵÉÁÕÕÏà·¨ÑéÖ¤»úеÄÜÊغ㶨ÂÉ£®¸Ãͬѧ½«Ò»ÖÊÁ¿Îªm=0.2kgµÄСÇòÊúÖ±ÉÏÅ×£¬»ñµÃ²¿·ÖÔ˶¯¹ý³ÌµÄƵÉÁÕÕƬÈçͼËùʾ£®ÒÑ֪ͼÖÐËù±êÊý¾ÝΪʵ¼Ê¾àÀ룬ƵÉÁÒÇÿ¸ô0.05sÉÁ¹âÒ»´Î£¬µ±µØÖØÁ¦¼ÓËÙ¶ÈΪ10m/s²£®¸Ãͬѧͨ¹ý¼ÆËãµÃµ½²»Í¬Ê±¿ÌµÄËÙ¶ÈÈçÏÂ±í£º

ʱ¿Ì	t2	t3	t4	t5
Ëٶȣ¨m/s£©	5.59	5.08	4.58

£¨1£©¸ù¾ÝƵÉÁÕÕƬÉϵÄÊý¾Ý¼ÆËãt₅ʱ¿ÌСÇòµÄËÙ¶Èv₅=4.08m/s£»
£¨2£©´Ót₂ʱ¿Ìµ½t₅ʱ¿Ì£¬Ð¡ÇòÖØÁ¦ÊÆÄܵÄÔö¼ÓÁ¿¡÷E_p=1.45J£¬¶¯ÄܵļõÉÙÁ¿¡÷E_k=1.46J£®¡¡ÔÚÎó²îÔÊÐíµÄ·¶Î§ÄÚ£¬Èô¡÷E_pÓë¡÷E_k½üËÆÏàµÈ£¬¾ÍÄÜÑéÖ¤»úеÄÜÊغ㶨ÂÉ£®£¨ÒÔÉϽá¹û¾ù±£ÁôÈýλÓÐЧÊý×Ö£©

Answer 1

·ÖÎö £¨1£©¸ù¾Ýij¶Îʱ¼äÄÚµÄƽ¾ùËٶȵÈÓÚÖмäʱ¿ÌµÄ˲ʱËÙ¶ÈÇó³öt₅ʱ¿ÌСÇòµÄËٶȣ®
£¨2£©¸ù¾ÝÉÏÉýµÄ¸ß¶ÈÇó³öÖØÁ¦ÊÆÄܵÄÔö¼ÓÁ¿£¬¸ù¾Ýt₂ʱ¿ÌºÍt₅ʱ¿ÌµÄ˲ʱËÙ¶ÈÇó³ö¶¯ÄܵļõСÁ¿£®

½â´ð ½â£º£¨1£©t₅ʱ¿ÌСÇòµÄËÙ¶Èv₅=$\frac{x}{2T}=\frac{£¨19.14+21.66£©¡Á1{0}^{-2}}{0.1}$m/s=4.08m/s£®
£¨2£©´Ót₂ʱ¿Ìµ½t₅ʱ¿Ì£¬Ð¡ÇòÖØÁ¦ÊÆÄܵÄÔö¼ÓÁ¿¡÷E_p=mgh=0.2¡Á10¡Á£¨26.68+24.16+21.66£©¡Á10^-2J=1.45J£¬t₂ʱ¿ÌµÄËÙ¶È${v}_{2}=\frac{x¡ä}{2T}=\frac{£¨29.18+26.68£©¡Á1{0}^{-2}}{0.1}$m/s=5.586m/s£®
Ôò¶¯ÄܵļõСÁ¿$¡÷{E}_{k}=\frac{1}{2}m{{v}_{2}}^{2}-\frac{1}{2}m{{v}_{5}}^{2}$=$\frac{1}{2}¡Á0.2¡Á£¨5.58{6}^{2}-4.0{8}^{2}£©$J=1.46J£®
¹Ê´ð°¸Îª£º£¨1£©4.08£¬£¨2£©1.45£¬1.46£®

µãÆÀ ±¾Ìâͨ¹ýƵÉÁÕÕƬÑéÖ¤»úеÄÜÊغ㣬ԭÀíÓëÖ½´øÏàËÆ£¬»á¸ù¾ÝÉÏÉýµÄ¸ß¶ÈÇó³öÖØÁ¦ÊÆÄܵÄÔö¼ÓÁ¿£¬»á¸ù¾ÝƵÉÁÕÕƬÇó½â˲ʱËٶȣ¬´Ó¶øµÃ³ö¶¯ÄܵļõСÁ¿£®