Question

1.Which is not an example of the measure of the frequency of a wave?

A.
4 waves per second

B.
5 hertz

C.
2 cycles per second

D.
0.10 s per wave



2.Which best describes what happens when a person sees a red leaf?

A.
The leaf radiates all colors of light except red to human eyes.

B.
Human eyes reflect red light back to the leaf.

C.
The leaf absorbs red light from human eyes.

D.
Red light reflected from the leaf enters human eyes.

Answer 1

1) Option D is not an example of the measure of the frequency of a wave. The frequency is defined as the number of waves or cycles per second. Its units can be waves/second or cycles/second. And The S.I. unit of frequency is Hertz. Therefore, The option D is invalid, as it is a meausre of the inverse of frequency i.e timeperiod. 2) Option D is the appropriate option. The Red light reflected from the leaf enters the human eye. When a person sees the red leaf, the red light from the leaf is reflected into our eyes and our eye receptors accept the red light. So, we are able to see the colour of leaf as red.

Answer 2

1.The frequency of a wave, when a wave passed through a medium, is described as how often the particles of the medium vibrated. Frequency tells how many complete vibrational cycles of a medium per given amount of time. True to this case, we can deduce then that the number of frequency would like to have the units of “cycle per second”, it can also be “waves per second”, “vibrations per second”. But, the widely used unit for frequency is Hertz, abbreviated as Hz. Where 1 hertz is equal to 1 cycle per second. Therefore, the answer to this item is letter D. 0.10s per wave. AS I MENTIONED EARLIER, FREQUENCY HAS THE UNITS : SOMETHING PER SECOND 2. On this item, the answer is: D.Red light reflected from the leaf enters human eyes.