I think it’s B I could be wrong but I tried lol
#1
Wavelength = 13 km
it vibrates 10 times each minute
so the frequency is defined by the number of vibrations per second
now the speed of wave is defined as
<em>so here velocity of wave is 2.2 km/s</em>
#2
Intensity of wave is directly proportional to the square of its amplitude
so we can say
k = constant
so if amplitude is doubled then its intensity will be increased by its square
<em>so intensity is 4 times</em>