2 thấu kính hội tụ có l1 và l2 cùng trục chính có tiêu cự là f1=30cm, f2=20cm. Quang tâm o1 và o2 của 2 thấu kính đó cách nhau 40cm.Điểm sáng A nằm trong khoảng giữa 2 thấu kính l1 và l2 cho ảnh A1 và A, cho A dao động điều hòa theo phương vuông góc với trục chính và có vị trí cân bằng nằm trên trục chính. Khi đó ảnh A1 và A2 cũng dao động theo phương vuông góc với trục chính và có đồ thị độ x(trục ox theo phương vuông góc trục chính) theo thời gian như hình vẽ.Diện tích tam giác A1AA2 lớn nhất gần bằng

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.