1) 1 nguon song dao dong voi tan so 20Hz. 2 diem tren phuong truyen song cach nhau 1 khoang 10cm luon dao dong nguoc pha nhau. Xac dinh toc do truyen song biet rang toc do truyen song = 0,8 m/s den 1m/s

1) 1 song co hoc duoc truyen tu diem O theo phuong Ox voi toc do v = 40cm/s. Nang luong song duoc bao toan dao dong tai nguon O co dang: u_o = 4cos \(\dfrac{\Pi}{2}t\)   (cm) 

a) T=? , λ ?

b) Viet phuong trinh song tai diem M: d = OM, u_M?. Xac dinh d de dao dong tai M cung pha voi dao dong tai O

c) Biet tai t: u_M = 3cm. Xac dinh li do tai M sau khoang Δt = 6(s)

1) Chi M dieu khien xe may vuot qua toc do cho phep nen da bi canh sat giao thong X lap bien ban va xu phat hanh chinh. Hanh vi cua canh sat giao thong X  la bieu hien cua hinh thuc thuc hien phap luat nao duoi day

A. Tuan thu phap luat     B. Ap dung phap luat

C. Su dung phap luat      D. Thi hanh phap luat

1) Sua loi va giai thich:

a) Because of urbanization continues, not only the infrastructure for health but also other social services in cities need improving

1) Viet phuong trinh : 

fructozo + AgNO₃ 

Fructozo + H₂

1) 1 con lac lo xo gom m = 100(g), K = 40N/m.

a) Tu vi tri can bang keo vat khoi vi tri can bang 1 doan 2\(\sqrt{3}\)cm roi truyen cho no van toc v = 40cm/s. Xac dinh bien do dao dong

b) Tinh nang luong cua he

c) Xac dinh dong nang cua he khi vat cach VTCB x = 1cm

1) Mot vat dao dong dieu hoa voi chu ky T = 3Δt va bien do A. Khi vat di thang ( theo 1 chieu) tu li do x = A den li do x = \(\dfrac{-A}{2}\) thi toc do trung binh cua vat bang: 

1) Lien Xo co thanh tuu gi vao nam 1972

1) Chung minh:

a) cos x - sin x = \(\sqrt{2}cos\left(x+\dfrac{\pi}{4}\right)\)

1) Tinh dao ham: 

y = x³(1-x)²