distance d = 5 km = 5 x 1000 m = 5000 m
time taken = 25 minute = 25 x 60 sec = 1500 sec
average velocity V = d/t
V = 5000/1500
V = 3.33 m/s towards east
Answer:
at r < R;
at 2R > r > R;
at r >= 2R
Explanation:
Since we have a spherically symmetric system of charged bodies, the best approach is to use Guass' Theorem which is given by,
(integral over a closed surface)
where,
= Electric field
= charged enclosed within the closed surface
= permittivity of free space
Now, looking at the system we can say that a sphere(concentric with the conducting and non-conducting spheres) would be the best choice of a Gaussian surface. Let the radius of the sphere be r .
at r < R,
= 0 and hence = 0 (since the sphere is conducting, all the charges get repelled towards the surface)
at 2R > r > R,
= Q,
therefore,
(Since the system is spherically symmetric, E is constant at any given r and so we have taken it out of the integral. Also, the surface integral of a sphere gives us the area of a sphere which is equal to 
)
or,
at r >= 2R
= 2Q
Hence, by similar calculations, we get,
Okay, I don't know if this question is supposed to be a trick question or not. The weight of the apple does not change as the plane travels up the atmosphere, but the MASS changes. Weight doesn't change no matter what environment you're in, but the mass changes in different environments. In this case, the weight is constant but the mass is decreasing as you go higher up.
Technology that does not harm the environment (environmental friendly technology)
Answer: 99.64 nm (≅ 100 nm)
Explanation: In order to explain this problem we have to obtain destructive inteference from two waves that reflect in the film and lens surface so both waves have a λ/2 shift then we have to get a difference path (2L) equal to an odd number of the half wavelegth.
Then we have the following expression:
L=(m+1/2)* λ/(2*n2); where n2 is the refractive index of the coating
for m=0 we have the minimum thickness for the coating
L=λ/(4*n2)=99.64 nm (≅ 100 nm)
