Answer
The rate at which the magnetic field is changing is
Explanation
From the question we are told that
The electric field strength is 
The radius is 
The rate of change of the magnetic field is mathematically represented as

Where
is change of a unit length

Where A is the area which is mathematically represented as

So
where L is the circumference of the circle which is mathematically represented as

So
![E (2 \pi r ) = (\pi r^2 ) [\frac{dB}{dt} ]](https://tex.z-dn.net/?f=E%20%282%20%5Cpi%20r%20%29%20%3D%20%20%28%5Cpi%20r%5E2%20%29%20%5B%5Cfrac%7BdB%7D%7Bdt%7D%20%5D)
![E = \frac{r}{2} [\frac{dB}{dt} ]](https://tex.z-dn.net/?f=E%20%20%3D%20%20%20%5Cfrac%7Br%7D%7B2%7D%20%20%5B%5Cfrac%7BdB%7D%7Bdt%7D%20%5D)
![[\frac{dB}{dt} ] = \frac{E}{ \frac{r}{2} }](https://tex.z-dn.net/?f=%5B%5Cfrac%7BdB%7D%7Bdt%7D%20%5D%20%3D%20%5Cfrac%7BE%7D%7B%20%5Cfrac%7Br%7D%7B2%7D%20%7D)
substituting values
![[\frac{dB}{dt} ] = \frac{3.5 *10^{-3}}{ \frac{15}{2} }](https://tex.z-dn.net/?f=%5B%5Cfrac%7BdB%7D%7Bdt%7D%20%5D%20%3D%20%5Cfrac%7B3.5%20%2A10%5E%7B-3%7D%7D%7B%20%5Cfrac%7B15%7D%7B2%7D%20%7D)
The colors that you see on the CD are created by white light reflecting from ridges in the metal. When light reflects off or passes through something with many small ridges or scratches, you often get rainbow colors and interesting patterns. They are called interference patterns.
The ozone layer is like the glass. the light from the sun enters the atmosphere and when the heat bounces back it is hard to escape the ozone layer therefore the earth's temperature rises
Answer:
Stars are at large distances that even light takes thousands of years to reach us from there.
for example, alpha centauri is 4300 light years away from earth and it is considered the nearest star to us, this means that light from there takes 4300 years to reach us and with a spaceships that can move with the speed of light is would take us 4300 years to get there which is imposible to live for that long.
hence, it is difficult to move between the stars.
One is chemo. Chemo is a special magnetic field like to treat cancer