ÌâÄ¿ÄÚÈÝ
8£®ÈçͼΪƤ´ø´«ËÍ×°ÖõÄʾÒâͼ£¬´«ËÍ´ø×ã¹»³¤£¬Çã½Ç¦È=37¡ã£¬´«ËÍ´øÕýÔÚÒÔv=2m/sµÄºã¶¨ËÙÂÊÄæʱÕëת¶¯£»ÔÚ´«ËÍ´øµ×¶Ë½«Ò»Îï¿éÒÔ´óСΪv0=8m/s³õËٶȻ¬ÉÏ´«ËÍ´ø£¬Îï¿éÓë´«ËÍ´ø¼äµÄ¶¯Ä¦²ÁÒòÊý¦Ì=0.5£®Ç󣺣¨g=10m/s2£¬sin 37¡ã=0.6£¬cos 37¡ã=0.8£©£¨1£©Îï¿éÑØ×Å´«ËÍ´øÄܹ»ÉÏ»¬µÄ×î´óλÒÆ£»
£¨2£©Îï¿é´Ó¿ªÊ¼µ½»¬»Ø´«ËÍ´øµ×¶Ë£¬¹²ÓöàÉÙʱ¼ä£®
·ÖÎö £¨1£©¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇóÉÏ»¬µÄ¼ÓËٶȣ¬ÔÙÓÉËÙ¶ÈλÒƹ«Ê½Çó×î´óλÒÆ£»
£¨2£©»¬¿éÔÚ´«ËÍ´øÉÏÏòÉÏÔ˶¯µÄʱ¼ä£¬ÏòÏÂ×öÔȼÓËÙÖ±Ïߣ¬ËÙ¶ÈÏàµÈºóÒÔÁíÒ»¼ÓËٶȼÌÐø×öÔȼÓËÙÖ±ÏßÔ˶¯£¬¸ù¾ÝÔ˶¯Ñ§¹«Ê½Çó³ö¸÷¸ö½×¶ÎµÄʱ¼ä£¬¼´¿ÉÇó³ö×Üʱ¼ä£»
½â´ð ½â£º£¨1£©Îï¿éÏòÉÏÔȼõËÙµ½Áã¡¢Éè¼ÓËÙ¶ÈΪa1¡¢Î»ÒÆΪs1¡¢Ê±¼äΪt1
ÓÉÅ£¶ÙµÚ¶þ¶¨ÂÉ£º$mgsin¦È+¦Ìmgcos¦È=m{a}_{1}^{\;}$ ¢Ù
½âµÃ ${a}_{1}^{\;}=10m/{s}_{\;}^{2}$
ÓÉËÙ¶ÈλÒƹ«Ê½£º${v}_{0}^{2}=2{a}_{1}^{\;}{s}_{1}^{\;}$ ¢Ú
µÃ ${s}_{1}^{\;}=3.2m$
£¨2£©ÉÏ»¬Ê±¼ä£º${t}_{1}^{\;}=\frac{{v}_{0}^{\;}}{{a}_{1}^{\;}}=0.8s$ ¢Û
Îï¿é·´Ïò¼ÓËÙµ½Óë´«ËÍ´øËÙ¶ÈÏàͬ
${a}_{2}^{\;}={a}_{1}^{\;}=10m/{s}_{\;}^{2}$ ¢Ü
Ï»¬µ½Óë´«ËÍ´øËÙ¶ÈÏàµÈ ${t}_{2}^{\;}=\frac{v}{{a}_{2}^{\;}}=0.2s$ ¢Ý
Ï»¬ÔȼÓËÙλÒÆ ${s}_{2}^{\;}=\frac{1}{2}{a}_{2}^{\;}{t}_{2}^{2}=0.2m$ ¢Þ
ÓÖÒòΪ¦Ì£¼tan¦È ËùÒÔÎï¿é¼ÌÐøÔȼÓËÙ
$mgsin¦È-¦Ìmgcos¦È=m{a}_{3}^{\;}$ ¢ß
µÃ ${a}_{3}^{\;}=2m/{s}_{\;}^{2}$
µ½´ïµØÃæ¹ý³Ì
${s}_{1}^{\;}-{s}_{2}^{\;}=v{t}_{3}^{2}+\frac{1}{2}a{t}_{3}^{2}$ ¢à
µÃ${t}_{3}^{\;}=1s$
ËùÒÔ´Ó¿ªÊ¼µ½Îï¿é»¬»Ø´«ËÍ´øµ×¶Ë£¬Îï¿é¹²ÓÃʱ
$t={t}_{1}^{\;}+{t}_{2}^{\;}+{t}_{3}^{\;}=2s$ ¢á
´ð£º£¨1£©Îï¿éÑØ×Å´«ËÍ´øÄܹ»ÉÏ»¬µÄ×î´óλÒÆ3.2m£»
£¨2£©Îï¿é´Ó¿ªÊ¼µ½»¬»Ø´«ËÍ´øµ×¶Ë£¬¹²ÓÃ2sʱ¼ä
µãÆÀ ½â¾ö±¾ÌâµÄ¹Ø¼üÀíÇåÎïÌåÔÚÕû¸ö¹ý³ÌÖеÄÔ˶¯¹æÂÉ£¬½áºÏÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½½øÐÐÇó½â£¬Çó³ö¸÷¶Î¹ý³ÌÖеļÓËÙ¶ÈÊǹؼü£®
A£® | $\frac{Pc}{h¦Ë}$ | B£® | $\frac{hc}{P¦Ë}$ | C£® | $\frac{¦ËP}{hc}$ | D£® | $\frac{¦Ëc}{hP}$ |
A£® | 2m/s | B£® | 4m/s | ||
C£® | 6m/s | D£® | 8m/s | ||
E£® | ÒòÅ׳öµã¸ß¶Èδ֪£¬¹ÊÎÞ·¨È·¶¨ |
A£® | ͼÏóÖÐv0=$\sqrt{5gR}$ | |
B£® | ͼÏóÖÐF0µÄÊýֵΪ4mg | |
C£® | ÈôÔ²¹ìµÀ²»¹â»¬£¬F0=7mg£¬Ôò°´Í¼ÖÐF0Ëù±íʾµÄ¶ÔÓ¦¹ý³Ì´ÓAµã¾¹ý°ë¸öÔ²Öܵ½´ïBµã£¬Ð¡Çò¿Ë·þĦ²ÁÁ¦×ö¹¦0.5mgR | |
D£® | ÈôÔ²¹ìµÀ²»¹â»¬£¬µ«¼ÙÉèСÇòÔ˶¯µ½»·µÄ¸÷´¦Ê±Ä¦²ÁÁ¦´óСÓëËÙ¶ÈÎ޹أ¬ÔòÉÏÊöÁ½ÌõF-v2ͼÏóÒÀȻƽÐÐ |
A£® | ¼ÓËÙµçѹԽ¸ß£¬µç×ÓÏÔ΢¾µµÄ·Ö±ç±¾ÁìÔ½¸ß | |
B£® | ¼ÓËÙµçѹԽ¸ß£¬µç×ÓÏÔ΢¾µµÄ·Ö±ç±¾ÁìÔ½µÍ | |
C£® | ͬµÈ¼ÓËÙµçѹÏ£¬µç×ÓÏÔ΢¾µµÄ·Ö±ç±¾Áì±ÈÖÊ×ÓÏÔ΢¾µµÄ·Ö±ç±¾Áì´ó | |
D£® | ͬµÈ¼ÓËÙµçѹÏ£¬µç×ÓÏÔ΢¾µµÄ·Ö±ç±¾Áì±ÈÖÊ×ÓÏÔ΢¾µµÄ·Ö±ç±¾ÁìС |
A£® | $\frac{F}{4}$ | B£® | $\frac{25F}{4}$ | C£® | $\frac{4F}{9}$ | D£® | $\frac{9F}{4}$ |
A£® | ¼ÓËÙ¶ÈaÓë¡÷v³ÉÕý±È£¬Óë¡÷t³É·´±È | |
B£® | ¡÷v±íʾÔÚ¡÷tʱ¼äÄÚÎïÌåËٶȵı仯Á¿£¬ËüµÄ·½Ïò²»Ò»¶¨Óë¼ÓËÙ¶ÈaµÄ·½ÏòÏàͬ | |
C£® | $\frac{¡÷v}{¡÷t}$±íʾËٶȵı仯ÂÊ£¬ÊDZêÁ¿ | |
D£® | ÀûÓÃa=$\frac{¡÷v}{¡÷t}$ÇóµÃµÄ¼ÓËÙ¶ÈÊÇ¡÷tʱ¼äÄÚµÄƽ¾ù¼ÓËÙ¶È |
A£® | ÎïÌåµÄËٶȷ¢Éú±ä»¯£¬Æ䶯ÄÜÒ»¶¨·¢Éú±ä»¯ | |
B£® | ÎïÌåµÄËٶȷ¢Éú±ä»¯£¬Æ䶯Á¿Ò»¶¨·¢Éú±ä»¯ | |
C£® | ÎïÌåµÄ¶¯Á¿·¢Éú±ä»¯£¬Æ䶯ÄÜÒ»¶¨·¢Éú±ä»¯ | |
D£® | ÎïÌåµÄ¶¯ÄÜ·¢Éú±ä»¯£¬Æ䶯Á¿Ò»¶¨·¢Éú±ä»¯ |