Answer:
0 J
Explanation:
Work is the product of force and distance in the direction of force.
The formula is ; Work = Force * Distance
Given that :
Force = 400 N
Distance = 0 meters
Work = 400 * 0 = 0 J
No work was done because the boulder did not move.
Intensity:
Decibels
Amplitude:
Meters
Frequency: Hertz
<u>Explanation:</u>
The Wave is not visible to eyes and they can easily propagate through vacuum. the average power travelling at a given period of time in a space is the intensity. Decibels is the measure of intensity. it is measured in the decibel scale. The wave's strength and the intensity gives the amplitude of wave. It is measured using meters.
The wave's amplitude and the energy has a direct proportionality. The number occurrence of wave cycles per second refers to the frequency of wave. it is measured in hertz. it is also measured as the number of cycles that occurs per second.
The gravitational force between two objects is given by

where
G is the gravitational constant
m1 and m2 are the masses of the two objects
r is the separation between the two objects
In this problem,

,

and

, therefore the gravitational force between the two objects is
The answer is C. An occluded front.