Gravitational potential energy = mass × gravity × height
Ep = (4)(9.81)(3)
Energy = 117.72 Joules
= 1.2x10^2 Joules
The energy of the wave will decrease.
The energy of a wave is given as
E = h f
where E = energy of waver
h = plank's constant
f = frequency of the wave.
From the formula , we see that the energy of the wave is directly proportional to the frequency of the wave. hence as the frequency of the wave decrease, the energy of the wave will decrease.
People will buy more of a good when its price falls and less when its price rises, according to the law of demand.