Shar bo‘laklari hajmi va sfera sirti
Javoblar ota-onalar va o‘qituvchilar uchun.
1
Sharning hajmi 288π. Radiusi va sirtini toping.
(4/3)R³ = 288, R³ = 216, R = 6; S = 4π · 36 = 144π.
2
R = 12 sferada balandligi 5 bo‘lgan qalpoq sirtini toping.
2π · 12 · 5 = 120π.
3
Radiusi 10 cm bo‘lgan metall shar eritilib, 8 ta teng sharchaga quyildi. Sharchaning radiusini va ularning umumiy sirti katta shar sirtidan necha marta ortiqligini toping.
Hajmlar: 8r³ = 1000, r = 5 cm. Umumiy sirt 8 · 4π · 25 = 800π cm², katta shar 400π cm²: 2 marta ko‘p.
4
R = 6, h = 4 bo‘lgan shar segmenti hajmini toping.
V = π · 16 · (18 − 4)/3 = 224π/3.
5
V = (4/3)πR³ va V = ⅓ S R dan S = 4πR² ni keltirib chiqaring.
S = 3V/R = 3 · (4/3)πR³/R = 4πR².