Answer:
87.5 m/s
Explanation:
The speed of a wave is given by

where
v is the wave speed
is the wavelength
f is the frequency
In this problem, we have
is the frequency
is the wavelength
Substituting into the equation, we find

Answer:
A. Speed
Explanation:
A vector quantity is a quantity which has both magnitude and direction. Here in the given options, speed is a scalar quantity but not the vector quantity.
Answer:
Can't understand the language
Explanation:
As we know that relation between energy and wavelength is as follows.
E = 
This means that energy is inversely proportional to wavelength. So, more is the energy of an electromagnetic radiation less will be its wavelength.
Also, f = 
Hence, less will be the wavelength more will frequency of a radiation.
Gamma rays are the rays that have highest energy, small wavelength and highest frequency.
Thus, we can conclude that gamma rays are the electromagnetic radiation which has the highest frequency.