初二一道物理题。关于密度的
\u51e0\u9053\u521d\u4e8c\u7684\u5bc6\u5ea6\u7269\u7406\u98981.
(15*24)/(200-80)=3
2.
\u94c1\u7684\u5bc6\u5ea6\uff1a7.9g/cm^2
234/7.9=30
\uff08\u4f53\u79ef\u662f80\u5e73\u65b9\u5398\u7c73\uff1f\uff1f\uff1f\uff1f\uff1f\uff09
\u7acb\u65b9\u5398\u7c73\u2026\u2026&
80-30=50
\u7a7a\u5fc3\u7684\uff0c\u4f53\u79ef50\u7acb\u65b9\u5398\u7c73
3.
9000/1=9000cm^3
100000/9000=11\uff08\u6c34\u7a3b\u7684\u5bc6\u5ea6\uff09
4.5*1000000/11=409090g=0.4\u5428
\u586b\u7a7a\uff1a
3.\u2014\u2014\u2014\u2014\u2014\u20141\uff1a2
4.\u4e0d\u76f8\u7b49\uff0c\u5bc6\u5ea6
5.\uff08\u62c9\u52302\u500d\u5427\uff1f\uff1f\uff1f\uff094\u500d\uff0c\u4e0d\u53d8
6.50\u5343\u514b\u63a8\u7406\u5f97\u523050\u5347\uff0c\u4f53\u79ef\u5c31\u662f\uff1a0.05\u7acb\u65b9\u7c73\u3002
\u670b\u53cb\u554a\u2026\u2026\u4f60\u5355\u4f4d\u9519\u597d\u591a\u2026\u2026
\u8003\u8bd5\u7684\u5355\u4f4d\u8981\u5c0f\u5fc3\u54e6
xiexie
\u5bc6\u5ea6\u516c\u5f0f\u03c1=m/v
\u5176\u4e2d\u5408\u91d1\u7684\u8d28\u91cfm=5
\u4f53\u79efv=2V0\uff08V0\u4e3a\u94c5\u6216\u94c1\u7684\u4f53\u79ef\uff09
\u03c1\u94c1*V0+\u03c1\u94c5*V0=5
\u6240\u4ee5v=2V0=2*5/\uff08\u03c1\u94c1+\u03c1\u94c5\uff09
\u6240\u4ee5\u5408\u91d1\u7684\u5bc6\u5ea6\u03c1=m/v=5/[2*5/\uff08\u03c1\u94c1+\u03c1\u94c5\uff09]=\uff08\u03c1\u94c1+\u03c1\u94c5\uff09/2
70g/m²=0.070kg/m²
0.01mm=0.00001m
0.070kg/m²÷0.00001m=7×10³kg/m³
∵m=ρv=ρsh
∴70g=ρ×1m2×5cm
70g=ρ50000cm
ρ=70g/50000cm=0.0014g/cm³=1.4Kg/m³
p纸=m\V=（m\S）\h=70g\cmsup3*0.01mm=70kg/msup3
绛旓細V=Sh=1銕∶0.01mm=1脳10^-5m³ 瀵嗗害=m梅V=0.07kg梅V=700kg/m³
绛旓細瀵嗗害鐨搴旂敤1锛庢湁涓涓摱瀛愯婊℃补鏃讹紝鎬昏川閲忔槸1.2kg锛岃婊℃按鏃舵昏川閲忔槸1.44kg锛屾按鐨勮川閲忔槸1.2kg锛屾眰娌圭殑瀵嗗害锛2锛庡皬鐡跺唴鐩涙弧姘村悗绉板緱璐ㄩ噺涓210g锛岃嫢鍦ㄧ摱鍐呭厛鏀句竴涓45g鐨勯噾灞炲潡鍚庯紝鍐嶈婊℃按锛岀О寰楃殑璐ㄩ噺涓251g锛屾眰閲戝睘鍧楃殑瀵嗗害锛3锛庝袱绉嶉噾灞炵殑瀵嗗害鍒嗗埆涓猴紝鍙栬川閲忕浉鍚岀殑杩欎袱绉嶉噾灞炲仛鎴愬悎閲戯紝璇...
绛旓細鐗╀綋鐨瀵嗗害鏄細270鍏/100绔嬫柟鍘樼背锛2.7鍏/绔嬫柟鍘樼背锛2700鍗冨厠姣忕珛鏂圭背锛
绛旓細璁撅細鐡剁殑璐ㄩ噺涓篗锛岀摱鐨勫绉负V銆傝В锛氳婊℃恫浣擄紝娑蹭綋鐨勪綋绉瓑浜庣摱鐨勫绉疺銆傝婊℃按鏃讹紝M+蟻姘碫=500M+1脳V=500M=500鈥1脳V 鈶犺婊￠厭绮炬椂锛孧+蟻閰扸=420M+0.8V=420 M=420鈥0.8V 鈶♀憼=鈶500鈥1脳V=420鈥0.8V0.2V=80鐡跺瓙鐨勫绉 V=400(cm3)灏哣鍊间唬鍏モ憼寮,鐡跺瓙鐨勮川閲廙=500...
绛旓細娉ユ矙姘寸殑璐ㄩ噺鏄300g锛屾祴鍑瀵嗗害鏄1.028g/cm 鍒欎綋绉槸300梅1.028鈮291.8绔嬫柟鍘樼背 鑰屾按鐨勫瘑搴︽槸1g/cm 鍒250鍏嬫按鐨勪綋绉负250绔嬫柟鍘樼背 鎵浠ラ粍鍦熺殑浣撶Н涓 291.8-250=41.8绔嬫柟鍘樼背 瀵嗗害涓50梅41.8鈮1.196g/cm
绛旓細V姘+V閰)鍥犱负鏈浣庤姹傛槸锛歏姘/(V姘+V閰)=10%锛浵侀厭V閰/(V姘+V閰)=90%锛屼笖鐭ワ細蟻姘=1000kg/m^3锛浵侀厭=800kg/m^3銆備唬鍏ヤ笂寮忓彲寰楋細蟻=820锛坘g/m^3锛夋墍浠ワ紝璇ュ巶鐢熶骇鐨勯厭绮瀵嗗害搴旀弧瓒筹細瀵嗗害灏忎簬0.82*10^3kg/m^3鍗冲彲銆傜瓟锛氳鍘傜敓浜х殑閰掔簿瀵嗗害搴斿皬浜0.82*10^3kg/m^3銆
绛旓細锛1锛瀵嗗害鏄 600/52=11.54g/cm3 (2锛夐噾銆侀摐鐨勮川閲忓垎鍒槸 300g 閭ｄ箞宸ヨ壓鍝佺殑瀵嗗害搴旇鏄600/锛300/19.3+300/8.9锛= 12.18g/cm3 鎵浠ヨ 鍞揣鍛 鐨勮瘽涓嶅彲淇 锛3锛夎閲戠殑浣撶Н鏄疿锛岄摐鐨勪綋绉槸Y 19.3*X+8.9*Y=600 X+Y=52 鍙互姹傚嚭X=13.19cm3 瀹為檯鍚噾閲忎负 19.3*13.19/600=...
绛旓細瀵嗗害蟻锛 璁句袱绉嶆恫浣撶殑浣撶Н涓篤锛屽垯m 1 =蟻 1 V,m 2 =蟻 2 V 娣峰悎鍚庢恫浣撶殑鎬昏川閲弇 鎬 =m 1 +m 2 =蟻 1 V+蟻 2 V=3脳10 3 V 3脳10 3 V 娣峰悎鍚庢恫浣撶殑鎬讳綋绉负2V 2V 娣峰悎鍚庢恫浣撶殑瀵嗗害蟻锛 = =1.5脳10 3 kg锛弇 3 ...
绛旓細閽㈢摱鐨勪綋绉紙v锛変笉鍙橈紝鐡跺唴鐨勬哀姘旂殑璐ㄩ噺鍑忓皯浜嗗洓鍒嗕箣涓锛屾墍浠ョ幇鍦ㄧ摱鍐呮哀姘旂殑璐ㄩ噺涓 3/4m锛屾墍浠瀵嗗害= 锛3/4m锛/ v =8涔樹互3/4=6
绛旓細锛1锛瀵嗗害鏄 600/52=11.54g/cm3 (2锛夐噾銆侀摐鐨勮川閲忓垎鍒槸 300g 閭ｄ箞宸ヨ壓鍝佺殑瀵嗗害搴旇鏄600/锛300/19.3+300/8.9锛= 12.18g/cm3 鎵浠ヨ鍞揣鍛樼殑璇濅笉鍙俊 锛3锛夎閲戠殑浣撶Н鏄疿锛岄摐鐨勪綋绉槸Y 19.3*X+8.9*Y=600 X+Y=52 鍙互姹傚嚭X=13.19cm3 瀹為檯鍚噾閲忎负 19.3*13.19/600=0....
