The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:
where I is the intensity and r is the distance from the source.
We can assume for instance that the initial distance from the source is r=1 m, so that we put
The intensity at r=3 m will be
Therefore, the sound intensity has decreased by a factor
.
Answer:
D
Explanation:
If two unequal forces act in opposite directions, one larger force must cancel out the smaller force,
leaving the net force to be some number in one direction.
Take for example a game of tug-of-war; there are two OPPOSITE forces (groups of people) acting on the rope, one force is pulling with a force in the negative direction while the other force is pulling in the positive direction.
If the forces on the rope were unequal, then the stronger force (group) will pull everything in their direction.
The same will happen on two unequal forces of opposite directions acting on a wooden block. Therefore, since the resultant force will have a non-zero magnitude and direction, there will be a change in the block's motion and position.
For any eclipse, all three bodies are in the same straight line. For a solar eclipse, the moon is the one in the middle. For a lunar eclipse, the Earth is the one in the middle.
Yes, <span> the moon fall partly into earth's shadow when it is in its full size</span>