Answer:
v = 8.4 m/s
Explanation:
The question ays, "A longitudinal wave has a frequency of 200 Hz and a wavelength of 4.2m. What is the speed of the wave?".
Frequency of a wave, f = 200 Hz
Wavelength = 4.2 cm = 0.042 m
We need to find the speed of the wave. The formula for the speed of a wave is given by :

So, the speed of the wave is equal to 8.4 m/s.
Answer:Decreases
Explanation:
Given
Volume is held constant that is it is a isochoric process.
We know that
PV=nRT
as n,V& R are constant therefore only variables are
P & T
so 

As
is decreasing therefore Pressure must also decrease so that ratio remains constant.
To solve this exercise it is necessary to use the concepts related to Difference in Phase.
The Difference in phase is given by

Where
Horizontal distance between two points
Wavelength
From our values we have,


The horizontal distance between this two points would be given for

Therefore using the equation we have




Therefore the correct answer is C.
The answer to your quesiton is,
A) Venus has phases.
-Mabel <3
Not sure.can you give me a clue?