Navoiy shahar 10-umumiy o’rta ta’lim maktabi 6- “ ” sinf o’quvchisi ning

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2-laboratoriya ishi

Mavzu: Shaynli tarozi yordamida jism massasini o’lchash

Kerakli asboblar. Shayinli tarozi toshlari bilan stakan, suv, massasi o‘lchanishi kerak bo‘lgan kub, shar, silindr shaklidagi jismlar.

Ishni bajarisli.

1. 
   Shayinli tarozining tuzilishi, turli massaga ega bo‘lgan tarozi toshlari bilan tanishish (16-rasm).
   
2. 
   Jism massasini o‘lchashdan oldin tarozi muvozanatga keltiriladi. Lozim bo‘lsa pallalarga qog‘oz parchalari qo‘yiladi.
   
3. 
   Massasi aniqlanadigan jismni tarozining chap pallasiga, toshlarini o‘ng pallasiga qo‘yiladi.
   
4. 
   Tarozini buzib qo‘ymaslik uchun toshni taxminan jism massasiga yaqinrog‘ini tanlab qo‘yiladi. Juda ko‘p farq qiluvchi toshni qo‘yganda tarozining og‘ishi chegaradan chiqib ketishi mumkin.
   
5. 
   Tarozi pallasiga ho‘l, iflos, issiq jismlarni qo‘yish mumkin emas. Unga suyuqlikni bevosita quyish, idishsiz sochilib ketuvchi narsalar (shakar, tuz)ni ham solish mumkin emas.
   
6. 
   Tarozida faqat uning pasportida yozilgan yukdan ortiqcha yukni tortish mumkin emas.
   
7. 
   Kichik massali toshchalarni faqat pinset (mo‘ychinak) yordamida idishidan olib pallaga qo‘yiladi. Chunki qo‘l bilan ushlansa, qo‘ldagi nam va yog‘ tosh- chaga o‘tib, uning massasiga ta’sir qilishi mumkin.
   

8. 
   Pallaga qo‘yilgan tosh yengil bo‘lsa, unga chamalab yengilroq toshdan : alab qo‘shib borish kerak.
   
9. 
   Tarozi muvozanatga kelib, strelkasi nolni ko‘rsatsa yoki u pallalar qo‘yilgan tomonlarning ko‘rsatkich uchlari bir to‘g‘ri chiziqqa kelsa, palladagi toshlar assalarining yig‘indisi hisoblanib yozib olinadi.
   
10. 
    Tarozida suvsiz bo‘sh stakan massasi m_st tortib olinadi (17-rasm).
    

11. Stakanni palladan olib, unga ma’lum miqdorda suv solinadi.

12. 
    Suvli stakanni tarozi pallasiga qo‘yib, massasi m_$tsuv o‘lchanadi.
    
13. 
    m = m _{st. suv.}— m_st formuladan stakandagi suv massasi hisoblanadi.
    

Izoh. Agar olchanadigan jism massasi sizda mavjud bo'lgan eng _ kichik tosh (20 mg) qo'yilganda ham ogir yoki yengil kelsa, umumiy massa yaxlitlab yoziladi. Masalan, 100g + 20g + lg + 500mg + 20mg bolganda og‘ir, 100g + 20g+ lg + 500 mg bo‘lganda yengil bo‘lsa, m ~ 121,5 gramm olinadi.

Nazorat savollari:

1. 
   Jismlar qizdirilganda uning massasi qanday o’zgaradi?
   
2. 
   Nima sababdan shaynli tarozida o’lchash, prujinali tarozida o’lchashga nisbatan aniqroq bo’ladi?
   
3. 
   Gaz massasini qanday usulda o’lchash mumkinligi haqida o’ylab ko’ring?
   

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