B\u00e0i 40 : Th\u1ef1c h\u00e0nh : X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng<\/h2>\n\n\n\n

I – M\u1ee4C \u0110\u00cdCH<\/h3>\n\n\n\n

   – Kh\u1ea3o s\u00e1t hi\u1ec7n t\u01b0\u1ee3ng c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng.<\/p>\n\n\n\n

   – X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a n\u01b0\u1edbc.<\/ins><\/p>\n\n\n\n

II – D\u1ee4NG C\u1ee4 TH\u00cd NGHI\u1ec6M<\/h3>\n\n\n\n

   1. L\u1ef1c k\u1ebf 0,1N c\u00f3 \u0111\u1ed9 chia nh\u1ecf nh\u1ea5t 0,001N.<\/p>\n\n\n\n

   2. V\u00f2ng kim lo\u1ea1i (nh\u00f4m) c\u00f3 d\u00e2y treo.<\/p>\n\n\n\n

   3. Hai c\u1ed1c nh\u1ef1a A, B \u0111\u1ef1ng n\u01b0\u1edbc, n\u1ed1i th\u00f4ng nhau b\u1eb1ng m\u1ed9t \u1ed1ng cao su Silicon (H\u00ecnh 40.1 SGK).<\/p>\n\n\n\n

   4. Th\u01b0\u1edbc k\u1eb9p c\u00f3 \u0111\u1ed9 chia nh\u1ecf nh\u1ea5t 0,1mm, ho\u1eb7c 0,05; 0,02 mm, Gi\u1edbi h\u1ea1n \u0111o 150mm (H\u00ecnh 40.3 SGK).<\/p>\n\n\n\n

   5. Gi\u00e1 treo c\u00f3 c\u01a1 c\u1ea5u n\u00e2ng h\u1ea1 c\u1ed1c \u0111\u1ef1ng ch\u1ea5t l\u1ecfng.<\/p>\n\n\n\n

III – C\u01a0 S\u1ede L\u00cd THUY\u1ebeT<\/h3>\n\n\n\n

   M\u1eb7t tho\u00e1ng c\u1ee7a ch\u1ea5t l\u1ecfng lu\u00f4n c\u00f3 c\u00e1c l\u1ef1c c\u0103ng, theo ph\u01b0\u01a1ng ti\u1ebfp \ntuy\u1ebfn v\u1edbi m\u1eb7t tho\u00e1ng. Nh\u1eefng l\u1ef1c c\u0103ng n\u00e0y l\u00e0m cho m\u1eb7t tho\u00e1ng c\u1ee7a ch\u1ea5t \nl\u1ecfng c\u00f3 khuynh h\u01b0\u1edbng co l\u1ea1i \u0111\u1ebfn di\u1ec7n t\u00edch nh\u1ecf nh\u1ea5t. Ch\u00fang \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \nnh\u1eefng l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t (hay c\u00f2n g\u1ecdi l\u00e0 l\u1ef1c c\u0103ng m\u1eb7t ngo\u00e0i) c\u1ee7a ch\u1ea5t l\u1ecfng.<\/p>\n\n\n\n

   C\u00f3 nhi\u1ec1u ph\u01b0\u01a1ng ph\u00e1p \u0111o l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t. Trong b\u00e0i n\u00e0y ta d\u00f9ng m\u1ed9t\n l\u1ef1c k\u1ebf nh\u1ea1y (lo\u1ea1i 0,1N), treo m\u1ed9t chi\u1ebfc v\u00f2ng b\u1eb1ng nh\u00f4m c\u00f3 t\u00ednh d\u00ednh \u01b0\u1edbt\n ho\u00e0n to\u00e0n \u0111\u1ed1i v\u1edbi ch\u1ea5t l\u1ecfng c\u1ea7n \u0111o (H\u00ecnh 40.2SGK).<\/p>\n\n\n\n

   Nh\u00fang \u0111\u00e1y v\u00f2ng ch\u1ea1m v\u00e0o m\u1eb7t ch\u1ea5t l\u1ecfng, r\u1ed3i k\u00e9o l\u00ean m\u1eb7t tho\u00e1ng. Khi\n \u0111\u00e1y v\u00f2ng v\u1eeba \u0111\u01b0\u1ee3c n\u00e2ng l\u00ean tr\u00ean m\u1eb7t tho\u00e1ng, n\u00f3 kh\u00f4ng b\u1ecb b\u1ee9t ngay ra \nkh\u1ecfi ch\u1ea5t l\u1ecfng: m\u1ed9t m\u00e0ng ch\u1ea5t l\u1ecfng xu\u1ea5t hi\u1ec7n, b\u00e1m quanh chu vi ngo\u00e0i v\u00e0 \nchu vi trong c\u1ee7a v\u00f2ng, c\u00f3 khuynh h\u01b0\u1edbng k\u00e9o v\u00f2ng v\u00e0o ch\u1ea5t l\u1ecfng. L\u1ef1c F_{c<\/sub>\n do m\u00e0ng ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng v\u00e0o v\u00f2ng \u0111\u00fang b\u1eb1ng t\u1ed5ng l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a \nch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean chu vi ngo\u00e0i v\u00e0 chu vi trong c\u1ee7a v\u00f2ng.<\/ins><\/p>\n\n\n\n}

   Do v\u00f2ng b\u1ecb ch\u1ea5t l\u1ecfng d\u00ednh \u01b0\u1edbt ho\u00e0n to\u00e0n, n\u00ean khi k\u00e9o v\u00f2ng l\u00ean kh\u1ecfi\n m\u1eb7t tho\u00e1ng v\u00e0 c\u00f3 m\u1ed9t m\u00e0ng ch\u1ea5t l\u1ecfng c\u0103ng gi\u1eefa \u0111\u00e1y v\u00f2ng v\u00e0 m\u1eb7t tho\u00e1ng, \nth\u00ec l\u1ef1c c\u0103ng F_{c<\/sub> c\u00f3 c\u00f9ng ph\u01b0\u01a1ng chi\u1ec1u v\u1edbi tr\u1ecdng l\u1ef1c P c\u1ee7a v\u00f2ng. Gi\u00e1 tr\u1ecb l\u1ef1c F \u0111o \u0111\u01b0\u1ee3c tr\u00ean l\u1ef1c k\u1ebf b\u1eb1ng t\u1ed5ng c\u1ee7a hai l\u1ef1c n\u00e0y: <\/p>\n\n\n\n}

         F = F_{c<\/sub> + P<\/p>\n\n\n\n}

   \u0110o P v\u00e0 F ta x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t F_{c<\/sub> t\u00e1c d\u1ee5ng l\u00ean v\u00f2ng.<\/p>\n\n\n\n}

   G\u1ecdi L_{1<\/sub> l\u00e0 chu vi ngo\u00e0i v\u00e0 L2<\/sub> l\u00e0 chu vi trong c\u1ee7a chi\u1ebfc v\u00f2ng, ta t\u00ednh \u0111\u01b0\u1ee3c h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t \u03c3 c\u1ee7a ch\u1ea5t l\u1ecfng \u1edf nhi\u1ec7t \u0111\u1ed9 nghi\u00ean c\u1ee9u theo c\u00f4ng th\u1ee9c:<\/p>\n\n\n\n}

<\/figure>\n\n\n\n

\u1edf \u0111\u00e2y D v\u00e0 d l\u00e0 \u0111\u01b0\u1eddng k\u00ednh ngo\u00e0i v\u00e0 \u0111\u01b0\u1eddng k\u00ednh trong c\u1ee7a v\u00f2ng<\/p>\n\n\n\n

IV – GI\u1edaI THI\u1ec6U D\u1ee4NG C\u1ee4 \u0110O<\/h3>\n\n\n\n

   1. Chi\u1ebfc v\u00f2ng nh\u00f4m d\u00f9ng trong th\u00ed nghi\u1ec7m n\u00e0y l\u00e0 lo\u1ea1i v\u1eadt r\u1eafn c\u00f3 \nt\u00ednh d\u00ednh \u01b0\u1edbt ho\u00e0n to\u00e0n \u0111\u1ed1i v\u1edbi ch\u1ea5t l\u1ecfng c\u1ea7n nghi\u00ean c\u1ee9u (n\u01b0\u1edbc). Tr\u01b0\u1edbc \nkhi \u0111o c\u1ea7n lau s\u1ea1ch c\u00e1c ch\u1ea5t b\u1ea9n b\u00e1m v\u00e0o m\u1eb7t v\u00f2ng, \u0111\u1ec3 c\u00f3 k\u1ebft qu\u1ea3 \u0111o \nch\u00ednh x\u00e1c.<\/p>\n\n\n\n

   2. Th\u01b0\u1edbc k\u1eb9p d\u00f9ng \u0111o chu vi ngo\u00e0i v\u00e0 chu vi trong c\u1ee7a chi\u1ebfc v\u00f2ng.<\/p>\n\n\n\n

      Th\u01b0\u1edbc k\u1eb9p: g\u1ed3m th\u01b0\u1edbc ch\u00ednh v\u00e0 du x\u00edch.<\/p>\n\n\n\n

   – \u0110\u1ecdc ph\u1ea7n ch\u00ednh (tr\u00ean th\u01b0\u1edbc ch\u00ednh);<\/p>\n\n\n\n

   – \u0110\u1ecdc ph\u1ea7n l\u1ebd: v\u1ea1ch tr\u00f9ng x \u0111\u1ed9 chia nh\u1ecf nh\u1ea5t(tr\u00ean du x\u00edch);<\/p>\n\n\n\n

   – K\u1ebft qu\u1ea3: ph\u1ea7n ch\u00ednh + ph\u1ea7n l\u1ebb.<\/p>\n\n\n\n

V – TR\u00ccNH T\u1ef0 TH\u00cd NGHI\u1ec6M<\/h3>\n\n\n\n

B\u00c1O C\u00c1O TH\u1ef0C H\u00c0NH<\/strong><\/p>\n\n\n\n

H\u1ecd v\u00e0 t\u00ean:……………………………………………L\u1edbp:…………….; Ng\u00e0y:………………………<\/p>\n\n\n\n

T\u00ean b\u00e0i th\u1ef1c h\u00e0nh:<\/p>\n\n\n\n

1. Tr\u1ea3 l\u1eddi c\u00e2u h\u1ecfi<\/strong><\/p>\n\n\n\n

a) N\u00eau v\u00ed d\u1ee5 v\u1ec1 hi\u1ec7n t\u01b0\u1ee3ng d\u00ednh \u01b0\u1edbt v\u00e0 hi\u1ec7n t\u01b0\u1ee3ng kh\u00f4ng d\u00ednh \u01b0\u1edbt c\u1ee7a ch\u1ea5t l\u1ecfng ?<\/p>\n\n\n\n

Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n

– Hi\u1ec7n t\u01b0\u1ee3ng d\u00ednh \u01b0\u1edbt: V\u00ec th\u1ee7y tinh b\u1ecb n\u01b0\u1edbc d\u00ednh \u01b0\u1edbt, n\u00ean gi\u1ecdt n\u01b0\u1edbc \nnh\u1ecf tr\u00ean m\u1eb7t b\u1ea3n th\u1ee7y tinh lan r\u1ed9ng th\u00e0nh m\u1ed9t h\u00ecnh c\u00f3 d\u1ea1ng b\u1ea5t k\u00ec.<\/p>\n\n\n\n

– Hi\u1ec7n t\u01b0\u1ee3ng kh\u00f4ng d\u00ednh \u01b0\u1edbt: th\u1ee7y tinh kh\u00f4ng b\u1ecb th\u1ee7y ng\u00e2n d\u00ednh \u01b0\u1edbt, \nn\u00ean gi\u1ecdt th\u1ee7y ng\u00e2n nh\u1ecf tr\u00ean m\u1eb7t b\u1ea3n th\u1ee7y tinh vo tr\u00f2n l\u1ea1i v\u00e0 b\u1ecb d\u1eb9t \nxu\u1ed1ng do t\u00e1c d\u1ee5ng c\u1ee7a tr\u1ecdng l\u1ef1c.<\/ins><\/p>\n\n\n\n

b) L\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t l\u00e0 g\u00ec ? N\u00eau ph\u01b0\u01a1ng ph\u00e1p d\u00f9ng l\u1ef1c k\u1ebf x\u00e1c \u0111\u1ecbnh l\u1ef1c \nc\u0103ng b\u1ec1 m\u1eb7t v\u00e0 x\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t ? Vi\u1ebft c\u00f4ng th\u1ee9c th\u1ef1c nghi\u1ec7m \nx\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1c\u0103ng b\u1ec1 m\u1eb7t theo ph\u01b0\u01a1ng ph\u00e1p n\u00e0y ?<\/p>\n\n\n\n

Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n

– L\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t: l\u00e0 l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean m\u1ed9t \u0111o\u1ea1n \u0111\u01b0\u1eddng nh\u1ecf b\u1ea5t k\u00ec tr\u00ean\n b\u1ec1 m\u1eb7t ch\u1ea5t l\u1ecfng lu\u00f4n c\u00f3 ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi \u0111o\u1ea1n \u0111\u01b0\u1eddng n\u00e0y v\u00e0 ti\u1ebfp \ntuy\u1ebfn v\u1edbi b\u1ec1 m\u1eb7t ch\u1ea5t l\u1ecfng, c\u00f3 chi\u1ec1u l\u00e0m gi\u1ea3m di\u1ec7n t\u00edch b\u1ec1 m\u1eb7t ch\u1ea5t l\u1ecfng\n v\u00e0 c\u00f3 \u0111\u1ed9 l\u1edbn f t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ed9 d\u00e0i l c\u1ee7a \u0111o\u1ea1n \u0111\u01b0\u1eddng \u0111\u00f3: f = \u03c3l.<\/p>\n\n\n\n

\u03c3 l\u00e0 h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t (su\u1ea5t c\u0103ng b\u1ec1 m\u1eb7t), \u0111\u01a1n v\u1ecb N\/m. <\/p>\n\n\n\n

Gi\u00e1 tr\u1ecb c\u1ee7a \u03c3 ph\u1ee5 thu\u1ed9c v\u00e0o nhi\u1ec7t \u0111\u1ed9 v\u00e0 b\u1ea3n ch\u1ea5t c\u1ee7a ch\u1ea5t l\u1ecfng: \u03c3 gi\u1ea3m khi nhi\u1ec7t \u0111\u1ed9 t\u0103ng.<\/p>\n\n\n\n

– Ph\u01b0\u01a1ng ph\u00e1p x\u00e1c \u0111\u1ecbnh:<\/p>\n\n\n\n

Nh\u00fang \u0111\u00e1y v\u00f2ng ch\u1ea1m v\u00e0o m\u1eb7t ch\u1ea5t l\u1ecfng, r\u1ed3i k\u00e9o l\u00ean m\u1eb7t tho\u00e1ng. Khi \n\u0111\u00e1y v\u00f2ng v\u1eeba \u0111\u01b0\u1ee3c n\u00e2ng l\u00ean tr\u00ean m\u1eb7t tho\u00e1ng, n\u00f3 kh\u00f4ng b\u1ecb b\u1ee9t ngay ra kh\u1ecfi\n ch\u1ea5t l\u1ecfng: m\u1ed9t m\u00e0ng ch\u1ea5t l\u1ecfng xu\u1ea5t hi\u1ec7n, b\u00e1m quanh chu vi ngo\u00e0i v\u00e0 chu \nvi trong c\u1ee7a v\u00f2ng, c\u00f3 khuynh h\u01b0\u1edbng k\u00e9o v\u00f2ng v\u00e0o ch\u1ea5t l\u1ecfng. L\u1ef1c F_{c<\/sub>\n do m\u00e0ng ch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng v\u00e0o v\u00f2ng \u0111\u00fang b\u1eb1ng t\u1ed5ng l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a \nch\u1ea5t l\u1ecfng t\u00e1c d\u1ee5ng l\u00ean chu vi ngo\u00e0i v\u00e0 chu vi trong c\u1ee7a v\u00f2ng.<\/p>\n\n\n\n}

Do v\u00f2ng b\u1ecb ch\u1ea5t l\u1ecfng d\u00ednh \u01b0\u1edbt ho\u00e0n to\u00e0n, n\u00ean khi k\u00e9o v\u00f2ng l\u00ean kh\u1ecfi \nm\u1eb7t tho\u00e1ng v\u00e0 c\u00f3 m\u1ed9t m\u00e0ng ch\u1ea5t l\u1ecfng c\u0103ng gi\u1eefa \u0111\u00e1y v\u00f2ng v\u00e0 m\u1eb7t tho\u00e1ng, \nth\u00ec l\u1ef1c c\u0103ng F_{c<\/sub> c\u00f3 c\u00f9ng ph\u01b0\u01a1ng chi\u1ec1u v\u1edbi tr\u1ecdng l\u1ef1c P c\u1ee7a v\u00f2ng. Gi\u00e1 tr\u1ecb l\u1ef1c F \u0111o \u0111\u01b0\u1ee3c tr\u00ean l\u1ef1c k\u1ebf b\u1eb1ng t\u1ed5ng c\u1ee7a hai l\u1ef1c n\u00e0y: <\/p>\n\n\n\n}

         F = F_{c<\/sub> + P<\/p>\n\n\n\n}

\u0110o P v\u00e0 F ta x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t F_{c<\/sub> t\u00e1c d\u1ee5ng l\u00ean v\u00f2ng.<\/p>\n\n\n\n}

– C\u00f4ng th\u1ee9c th\u1ef1c nghi\u1ec7m x\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t:<\/p>\n\n\n\n

<\/figure>\n\n\n\n

2. K\u1ebft qu\u1ea3<\/strong><\/p>\n\n\n\n

* B\u1ea3ng 40.1<\/p>\n\n\n\n

\u0110\u1ed9 chia nh\u1ecf nh\u1ea5t c\u1ee7a l\u1ef1c k\u1ebf: 0,001N\n\t\t<\/td><\/tr>
L\u1ea7n \u0111o\t<\/td>	P (N)\t<\/td>	F(N)\t<\/td>	Fc<\/sub> = F \u2013 P (N)\t<\/td>	\u0394Fc<\/sub>(N)<\/td><\/tr>
1\t<\/td>	0,047\t<\/td>	0,061\t<\/td>	0,014\t<\/td>	0,001 <\/td><\/tr>
2\t<\/td>	0,046\t<\/td>	0,061\t<\/td>	0,015\t<\/td>	0 <\/td><\/tr>
3\t<\/td>	0,046\t<\/td>	0,062\t<\/td>	0,016\t<\/td>	0,001 <\/td><\/tr>
4\t<\/td>	0,047\t<\/td>	0,062\t<\/td>	0,015\t<\/td>	0 <\/td><\/tr>
5\t<\/td>	0,046\t<\/td>	0,060\t<\/td>	0,014\t<\/td>	0,001 <\/td><\/tr>
Gi\u00e1 tr\u1ecb trung b\u00ecnh\t<\/td>	0,0464\t<\/td>	0,0612\t<\/td>	0,015\t<\/td>	0,0006 <\/td><\/tr><\/tbody><\/table>\n\n\n\n * B\u1ea3ng 40.2<\/p>\n\n\n\n \u0110\u1ed9 chia nh\u1ecf nh\u1ea5t c\u1ee7a th\u01b0\u1edbc k\u1eb9p: 0,05mm\n\t\t<\/td><\/tr> L\u1ea7n \u0111o\t<\/td> D (mm)\t<\/td> \u0394D(mm)\t<\/td> d (mm)\t<\/td> \u0394d(mm) <\/td><\/tr> 1\t<\/td> 51,5\t<\/td> 0,16\t<\/td> 50,03\t<\/td> 0,004 <\/td><\/tr> 2\t<\/td> 51,6\t<\/td> 0,06\t<\/td> 50,02\t<\/td> 0,006 <\/td><\/tr> 3\t<\/td> 51,78\t<\/td> 0,12\t<\/td> 50,03\t<\/td> 0,004 <\/td><\/tr> 4\t<\/td> 51,7\t<\/td> 0,04\t\t<\/td> 50,02\t<\/td> 0,006 <\/td><\/tr> 5\t<\/td> 51,7\t<\/td> 0,04\t<\/td> 50,03\t<\/td> 0,004 <\/td><\/tr> Gi\u00e1 tr\u1ecb trung b\u00ecnh\t<\/td> 51,66\t<\/td> 0,08\t<\/td> 50,03\t<\/td> 0,005 <\/td><\/tr><\/tbody><\/table>\n\n\n\n a) C\u00e1c k\u1ebft qu\u1ea3 t\u00ednh \u0111\u01b0\u1ee3c \u0111\u01b0\u1ee3c ghi nh\u01b0 trong b\u1ea3ng 40.1 v\u00e0 40.2<\/p>\n\n\n\n b) Gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a n\u01b0\u1edbc:<\/p>\n\n\n\n <\/figure>\n\n\n\n c) T\u00ednh sai s\u1ed1 t\u1ec9 \u0111\u1ed1i c\u1ee7a ph\u00e9p \u0111o:<\/p>\n\n\n\n <\/figure>\n\n\n\n Trong \u0111\u00f3:<\/p>\n\n\n\n <\/figure>\n\n\n\n \n (\u0394F\u2019 l\u00e0 sai s\u1ed1 d\u1ee5ng c\u1ee5 c\u1ee7a l\u1ef1c k\u1ebf, l\u1ea5y b\u1eb1ng m\u1ed9t n\u1eefa \u0111\u1ed9 chia nh\u1ecf nh\u1ea5t c\u1ee7a l\u1ef1c k\u1ebf \u2192 \u0394F\u2019 = 0,001\/2 = 0,0005)<\/p>\n\n\n\n <\/figure>\n\n\n\n \n (\u0394D\u2019 v\u00e0 \u0394d\u2019 l\u00e0 sai s\u1ed1 d\u1ee5ng c\u1ee5 c\u1ee7a th\u01b0\u1edbc k\u1eb9p, l\u1ea5y b\u1eb1ng m\u1ed9t n\u1eefa \u0111\u1ed9 chia nh\u1ecf nh\u1ea5t c\u1ee7a th\u01b0\u1edbc k\u1eb9p \u2192 \u0394D\u2019 = \u0394d\u2019 = 0,05\/2 = 0,025 mm)<\/p>\n\n\n\n <\/figure>\n\n\n\n \u2192 \u0394Fc<\/sub> = 0,0006 + 2. 0,0005 = 0,0016 \n<\/p>\n\n\n\n V\u00e0 \u0394D = 0,08 + 0,025 = 0,105 mm; \u0394d = 0,005 + 0,025 = 0,03 mm<\/p>\n\n\n\n <\/figure>\n\n\n\n <\/figure>\n\n\n\n <\/figure>\n\n\n\n Nh\u01b0 v\u1eady trong tr\u01b0\u1eddng h\u1ee3p n\u00e0y ta ph\u1ea3i l\u1ea5y \u03c0 = 3,1412 \u0111\u1ec3 cho \n khi \u0111\u00f3 ta c\u00f3 th\u1ec3 b\u1ecf qua \n<\/p>\n\n\n\n <\/figure>\n\n\n\n d) T\u00ednh sai s\u1ed1 tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ph\u00e9p \u0111o: <\/p>\n\n\n\n <\/figure>\n\n\n\n e) Vi\u1ebft k\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a n\u01b0\u1edbc:<\/p>\n\n\n\n <\/figure>\n\n\n\n C\u00e2u h\u1ecfi<\/h3>\n\n\n\n B\u00e0i 1 (trang 222 SGK V\u1eadt L\u00fd 10). C\u00f3 th\u1ec3 d\u00f9ng l\u1ef1c k\u1ebf nh\u1ea1y \u0111\u1ec3 \u0111o l\u1ef1c \nc\u0103ng b\u1ec1 m\u1eb7t v\u00e0 h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng kh\u00f4ng d\u00ednh \u01b0\u1edbt theo \nph\u01b0\u01a1ng ph\u00e1p n\u00eau trong b\u00e0i \u0111\u01b0\u1ee3c kh\u00f4ng?<\/p>\n\n\n\n Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n Ta c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng l\u1ef1c k\u1ebf nh\u1ea1y \u0111\u1ec3 \u0111o l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t v\u00e0 h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 \nm\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng kh\u00f4ng d\u00ednh \u01b0\u1edbt theo ph\u01b0\u01a1ng ph\u00e1p n\u00eau trong b\u00e0i.<\/p>\n\n\n\n B\u00e0i 2 (trang 222 SGK V\u1eadt L\u00fd 10). Trong b\u00e0i th\u00ed nghi\u1ec7m n\u00e0y, t\u1ea1i sao \nkhi m\u1ee9c n\u01b0\u1edbc trong b\u00ecnh A h\u1ea1 th\u1ea5p d\u1ea7n th\u00ec gi\u00e1 tr\u1ecb ch\u1ec9 tr\u00ean l\u1ef1c k\u1ebf l\u1ea1i \nt\u0103ng d\u1ea7n?<\/p>\n\n\n\n Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n Khi n\u01b0\u1edbc trong b\u00ecnh A h\u1ea1 th\u1ea5p d\u1ea7n th\u00ec l\u1ef1c \u0111\u1ea9y Ac-xi-met Fa s\u1ebd gi\u1ea3m \nd\u1ea7n, v\u00ec v\u1eady n\u00f3 s\u1ebd d\u1ea7n nh\u1ecf h\u01a1n tr\u1ecdng l\u1ef1c P c\u1ee7a v\u00f2ng nh\u00f4m, P > Fa \u21d2 \nv\u00f2ng nh\u00f4m h\u1ea1 th\u1ea5p d\u1ea7n \u0111\u1ebfn khi d\u00e2y gi\u1eef v\u00f2ng \u0111\u1ea1t \u0111\u1ebfn gi\u1edbi h\u1ea1n \u0111\u00e0n h\u1ed3i. M\u1eb7t\n kh\u00e1c, do v\u00f2ng nh\u00f4m kh\u00f4ng d\u00ednh \u01b0\u1edbt n\u00ean l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a n\u01b0\u1edbc n\u00edu gi\u1eef \nb\u1ec1 m\u1eb7t v\u00f2ng nh\u00f4m khi\u1ebfn n\u00f3 b\u1ecb k\u00e9o xu\u1ed1ng, \u0111\u1ebfn khi gi\u00e1 tr\u1ecb l\u1ef1c c\u0103ng b\u1ec1 m\u1eb7t \nc\u1ee7a n\u01b0\u1edbc \u0111\u1ea1t c\u1ef1c \u0111\u1ea1i, l\u1ef1c t\u01b0\u01a1ng t\u00e1c gi\u1eefa c\u00e1c ph\u00e2n t\u1eed n\u01b0\u1edbc kh\u00f4ng c\u00f2n \u0111\u1ee7 \ns\u1ee9c h\u00fat n\u00ean ch\u00fang b\u1ecb ” \u0111\u1ee9t” “bu\u00f4ng tha” cho v\u00f2ng nh\u00f4m.<\/p>\n\n\n\n B\u00e0i 3 (trang 222 SGK V\u1eadt L\u00fd 10). So s\u00e1nh gi\u00e1 tr\u1ecb c\u1ee7a h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 \nm\u1eb7t x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c trong th\u00ed nghi\u1ec7m n\u00e0y v\u1edbi gi\u00e1 tr\u1ecb h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t \u03c3 \nc\u1ee7a n\u01b0\u1edbc c\u1ea5t \u1edf 20\u00baC ghi trong B\u1ea3ng 37.1, s\u00e1ch gi\u00e1o khoa? N\u1ebfu c\u00f3 sai l\u1ec7ch\n th\u00ec nguy\u00ean nh\u00e2n t\u1eeb \u0111\u00e2u?<\/p>\n\n\n\n Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n H\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t trong th\u00ed nghi\u1ec7m th\u01b0\u1eddng nh\u1ecf h\u01a1n gi\u00e1 tr\u1ecb th\u1ef1c t\u1ebf \ntrong SGK (\u03c3 = 0,073N\/m) v\u00ec trong SGK l\u00e0m th\u00ed nghi\u1ec7m \u1edf m\u00f4i tr\u01b0\u1eddng l\u00ed \nt\u01b0\u1edfng n\u01b0\u1edbc c\u1ea5t, c\u00f2n trong ph\u00f2ng th\u00ed nghi\u1ec7m \u0111\u1ed9 tinh khi\u1ebft c\u1ee7a n\u01b0\u1edbc v\u00e0 c\u1ee7a\n v\u00f2ng nh\u00f4m kh\u00f4ng l\u00ed t\u01b0\u1edfng, c\u00f3 sai s\u1ed1 trong qu\u00e1 tr\u00ecnh \u0111o. Ngo\u00e0i ra \u03c3 c\u00f2n \nph\u1ee5 thu\u1ed9c v\u00e0o nhi\u1ec7t \u0111\u1ed9 c\u1ee7a m\u00f4i tr\u01b0\u1eddng.<\/p>\n\n\n\n B\u00e0i 4 (trang 222 SGK V\u1eadt L\u00fd 10). Sai s\u1ed1 c\u1ee7a ph\u00e9p \u0111o h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t \u03c3 trong b\u00e0i th\u1ef1c h\u00e0nh ch\u1ee7 y\u1ebfu g\u00e2y ra do nguy\u00ean nh\u00e2n n\u00e0o?<\/p>\n\n\n\n Tr\u1ea3 l\u1eddi:<\/strong><\/p>\n\n\n\n Sai s\u1ed1 h\u1ec7 th\u1ed1ng: sai s\u1ed1 d\u1ee5ng c\u1ee5 \u0111o.<\/p>\n\n\n\n Sai s\u1ed1 ng\u1eabu nhi\u00ean:<\/p>\n\n\n\n + Sai s\u1ed1 trong qu\u00e1 tr\u00ecnh \u0111o: kh\u00f4ng l\u00e0m \u0111\u00fang th\u00ed nghi\u1ec7m, k\u0129 n\u0103ng th\u1ef1c \nh\u00e0nh k\u00e9m, \u0111i\u1ec1u ki\u1ec7n th\u1ef1c h\u00e0nh g\u1eb7p tr\u1edf ng\u1ea1i: gi\u00f3, s\u1ee9c c\u1ea3n kh\u00f4ng kh\u00ed,\u2026<\/p>\n\n\n\n + Sai s\u1ed1 trong qu\u00e1 tr\u00ecnh t\u00ednh to\u00e1n: l\u1ea5y tr\u00f2n s\u1ed1 khi t\u00ednh, t\u00ednh sai,\u2026<\/ins><\/p>\n\n\n\n + Sai s\u1ed1 do nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng c\u00f3 th\u1ec3 bi\u1ebfn \u0111\u1ed9ng nh\u1eb9 trong th\u1eddi \u0111i\u1ec3m l\u00e0m th\u1ef1c nghi\u1ec7m.<\/p>\n","protected":false},"excerpt":{"rendered":" B\u00e0i 40 : Th\u1ef1c h\u00e0nh : X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng I – M\u1ee4C \u0110\u00cdCH    – Kh\u1ea3o s\u00e1t hi\u1ec7n t\u01b0\u1ee3ng c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a ch\u1ea5t l\u1ecfng.    – X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 c\u0103ng b\u1ec1 m\u1eb7t c\u1ee7a n\u01b0\u1edbc. II – D\u1ee4NG C\u1ee4 TH\u00cd NGHI\u1ec6M    1. L\u1ef1c k\u1ebf 0,1N c\u00f3 \u0111\u1ed9 chia nh\u1ecf […]<\/p>\n","protected":false},"author":12,"featured_media":44209,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[1640],"tags":[],"yoast_head":"\n