The Planck’s Equation states that
E = hv
E stands for energy measured in Joules
v stands for frequency measured in s^-1 or Hertz (Hz)- 1Hz .
h is Planck’s constant which is equivalent to 6.626x10-34 J.s
The Planck's equation states that the energy of a photon, is directly proportional to its frequency (v), by a constant factor (h).
Given:
E=3.2 * 10^-24 J
h= 6.626x10-34 J.s
Now we know that
E=hv
Thus substituting the given values we get
v=3.2 * 10^-24 /6.626x10-34
v=48 x 10^9 s^-1
