Explanation:
A simple way to state Newton's first law is:
For every action force, there is a reaction force which is equal in magnitude and opposite in direction.
Usually to preserve the organisms (maybe the organisms are endangered species or need to be protected in some other way). Another reason could be for the benefit of mankind (for example, an artificial river provides recreational purposes)
A is an example of physical change
Answer:
Radius of bigger loop(R) =4.5cm
Explanation:
Consider a circular path of radius r around the wire. The magnetic field along that path is given by
;
∫B*dl = k*I where I is the current enclosed. From symmetry, ∫B*dl = 2*π*r*B
B = K*I/r, so the magnetic field varies inversely as the loop radius and directly as the current.
The smaller loop current to radius ratio is 12/2.7
The bigger loop current to radius ratio is = 20/R
12/2.7 = 20/R
R = (20 * 2.7)/12
R=54/12
R=4.5cm
Vì khi chiếu tia tới vuông góc một mặt phẳng gương, tia tới trùng với pháp tuyển, góc tới bằng góc phản xạ bằng 0.
