N
namcham


cho mot soi day 40 cm,2 dau co dinh. v song truyen tren soi day=200 cm/s
phai tang f tu muc am co ban 1 luong nho nhat = bao nhieu de tren day lai co song dung khi:
a,1 dau co dinh, 1dau tu do
b,2 dau co dinh
Cau noi cach lam chung cho kieu bai nay,roi hay lam cu the!!!!!!!!!!
CAM ON!!!!!!!!!11
phai tang f tu muc am co ban 1 luong nho nhat = bao nhieu de tren day lai co song dung khi:
a,1 dau co dinh, 1dau tu do
b,2 dau co dinh
Cau noi cach lam chung cho kieu bai nay,roi hay lam cu the!!!!!!!!!!
CAM ON!!!!!!!!!11