As it is given that Bulk modulus and density related to velocity of sound

by rearranging the equation we can say

now we need to find the SI unit of Bulk modulus here
we can find it by plug in the units of density and speed here

so SI unit will be

SO above is the SI unit of bulk Modulus
KE = 1/2mv^2
KE= 1/2(2)(5)^2
KE= 25 J
It moved from 0 cm to 4 cm at a constant speed of 1 cm/s.