Answer:
By reflection
Explanation:
The light energy can be transported by the means of transmitting it by reflecting it to several surfaces . as we know , light doesn't need any medium to travel . Electromagnetic waves are used to transmit them .
The temperature inside the copper rod varies linearly with the distance from the hot end of the rod. This means that we can find the temperature at 23 cm (let's call it 'point A') from the cool end by solving a linear proportion.
The temperature difference between the two ends of the rod is

and this corresponds to a length of 81 cm. Therefore, we can write:

from which we find

This is not the final answer actually; this is the temperature difference between the cool end and point A. So, the temperature at point A is
The strong magnetic fields is Long rang attractive power Reuther then week magnetic field.
B. Extra text to get to 20 characters.