. Ap dung BDT a r+ b1 +i > 456 vir cong thrlc GW Lei,bniz:
Ldi gi:ii Kf hiOu M ,m tndng fng la khdi luong ban ddu cira v0 tinh vl khdi luong cria
luong ban ddu cira v0 tinh vl khdi luong cria
tram. Dd c6 loi vd mat nang luong, truydn cho
tram vAn tdc i cilng hudng vdi vAn toc il cira
v6 tinh, khi d6 v6 tinh thu van toc i hu6ng
ngudc lai. Ap dung dinh luAt bao toin d6ng
;M,
luong: Mto-ntu-(M -nr)t' , vdi r11 =,/G-v 2l?
(vi vC tinh chuydn d6ng tr6n quy dao trdn bdn
kinh 2R; Mdldkhdi luong trr{i ddt).
Tt d6 _=_ ttl ](y *v (l)
M u+v
Cd nang toin phdn cta tram hic ph6ng bang
kh6ng: Yt- - G''Y-u = o, suy ra
tr^L,
u= l-
- \i R
Theo dinh luAt bio toirn nang luong:
(M -nt)t': ^lM _ rtt)M,r - ri - 22R (M -rtr)t"1 _, ^1M .- _ ttr\M,1 2R
vdi v' lh vAn toc tai didm tidp ddt. Mat
theo dinh luAt Kepler: 2Rv = Rt"
Tu (3) v) (4) tim duoc r' = ,F9 .
!3R
khiic,
(4)
Thay cdc gi6 tri cua I'1i, t'vit rr viro (1) ta duoc:
,t V7 _- 'JJ --0.8t.
M Jz*Jo
Nhrin x6t. Ciic ban sau c6 ldi giAi dfng vi gon:
Vinh Phric: \,'ir Ngoc Qutttrg, l2A, THP| chuy0n Vinh
Phric: Phri Tho: Plnnt Ddng Htii, l2C, '|HPT Hing
Vudng; Bic Ninh: Trtin Tlfii Hd, 12 Li, THPI' chuyen
Bic Ninh; Hi Ndi: Trdtr DhfiVinh. I lAl. THPT Ngoc
Hdi; Hiii Phdng: Dito Hiii Anh, l0 Li, THPT NK Trdn
Phi; Hrmg YEn: Triin Klfinlt Hoitn, llAl' THPT Yen
M9; Thrii Binh: ,N.qrr.vditVdnTldtit, 11A1. THPT Nam
Tidn Hrii; Thanh H6az Plnm Kltic Tltirtlt. I lA, THFrf
Tri€u Son III; Ngh6 An: Li Dinlr Kltii|. 10A3, THTI
chuy€n Phan Boi Chdu, Lai Kin Klttirilr. t1A'+ Li, kh6i THPT chuy€n. DH Vinh; Qu:ing Ngai: Ngrr,r'rtrr Thi Kint Kltrty€tt, I I Li. THIT chuyCn L0 Khietl Binh Dinh:
Ngrr,vlrr )'itt Atir, l0L, THFrf L0 Qu! DOn, Qul' Nhctn.
N{AI ANH