Answer:
The difference between ice and steam in Celsius (Centigrade) is 100 deg.
So the difference between and 4 cm and 24 cm of the thread corresponds to 100 deg C.
So 8 cm is 4 cm greater than the ice point
4 cm / 20 cm = 1/5 since the steam point and the ice point are 20 cm apart
Then 1/5 * 100 deg C = 20 deg C the requested temperature
D is correct, Gamma rays have the shortest wavelength.
<em>A statement that is true for ALL of the examples of electromagnetic waves is that;</em>
A) They all move at the same speed in a vacuum
<u>The reason for qualifying 'in vacuum' is because EM waves of different frequencies often propagate at different speeds through material. Generally speaking, we say that light travels in waves, and all electromagnetic radiation travels at the same speed which is about 3.0 * 108 meters per second through a vacuum.</u>