When the amplitude of a wave triples, the intensity changes by a factor of [blank](1/3,1/9,3,9)
when the amplitude of a wave is cut in half, the intensity changes by a factor of [blank](1/4,1/2,2,4)
when the distance between the source and your ear is ten times farther away, the intensity changes by a factor of {blank](1/10,1/100,10,100)
when the distance between the source and your ear is reduced by 1/3, the intensity changes by a factor of [blank](1/3,1/9,3,9)

1. It becomes 9 times.

2. it becomes one fourth times.

3. It becomes one hundredth times.

4. It becomes one ninth times.

Explanation:

Intensity of a wave is directly proportional to the square of amplitude of the wave and inversely proportional to the square of the distance between the source and observation point.

1. As the amplitude of the wave is tripled, the intensity becomes 9 times.

2. As the amplitude becomes half, the intensity becomes one fourth.

3. As the distance between the source and the ear is one tenth, the intensity becomes one hundredth.

4. As the distance between source and ear is one third, the intensity becomes one ninth.

answer a fan shaped mass of sediment deposited at the base of a mountain front do to an abrupt change in stream gradient;