53
Quvlama harakat
Darslik: 2-qism, 53-dars, 43–45-betlar
MaqsadQuvlama harakatga doir masalalar: vaqt, tezlik va oraliqni topish.
Yangi so‘zlar
oraliq · gapquvib yetish · catching uporqadagi · the one behindoldindagi · the one ahead
Tushuntirish
Quvlama masalalarida uch kattalik bog‘langan: oraliq S, quvish tezligi v₂ − v₁ va vaqt t. S = (v₂ − v₁) × t, t = S : (v₂ − v₁), v₂ = S : t + v₁. Masalan, oraliq 30 km, 5 h da yetib olish uchun oldindagi 55 km/h bo‘lsa, orqadagi 30 : 5 + 55 = 61 km/h bilan yurishi kerak. Vaqt o‘tgach oraliq: S − (v₂ − v₁) × t.
Namunalar
Oraliq 24 km, 14 va 10 km/h: 24 : (14 − 10) = 6 h.
Oraliq 40 km, 70 va 60 km/h: 3 h dan keyin 40 − (70 − 60) × 3 = 10 km.
Sinfda faoliyat
«Qanday tezlikda yetamiz?»: bolalar oraliq va vaqtni tanlab, kerakli tezlikni hisoblaydi.
Mashq
1
Orqadagi velosipedchi 14 km/h, oldindagisi 10 km/h tezlikda, oraliq 24 km. Necha soatda yetib oladi?
6
2
Oraliq 30 km. Oldindagi mashina 55 km/h tezlikda. Orqadagi mashina 5 h da yetib olishi uchun necha km/h bilan yurishi kerak?
61
3
Oraliq 40 km, orqadagi 70 km/h, oldindagi 60 km/h. 3 h dan keyin oraliq necha km?
10
4
Oraliq 20 km, orqadagi mashina 80 km/h, oldindagisi 70 km/h. Yetib olguncha orqadagi mashina necha km yuradi?
160