Answer:
D) The energy is quadrupled.
Step-by-step explanation:
Bobs found out from his study that energy of a wave is directly proportional to the square of the waves amplitude. This is expressed as:
E = kA² where:
E is the energy
A is the amplitude
k is the proportionality constant.
If the amplitude change from 2m to 4m, the initial amplitude is 2m and the final amplitude is 4m.
When A is 2m
E = k(2)²
E1 = 4K ... 1
As the amplitude increase to 4m, to energy becomes
E2 = k(4)²
E2 = 16k... 2
Taking the ratio of equation 2 to one to get the new energy E2 in terms of E1 will give:
E2/E1 = 16k/4k
E2/E1 = 4
E2 = 4E1
This shows that as the amplitude increases from 2m to 4m, the energy quadrupled