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:
![I(r)= \frac{1}{r^2}](https://tex.z-dn.net/?f=I%28r%29%3D%20%5Cfrac%7B1%7D%7Br%5E2%7D%20)
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
![I= \frac{1}{r^2}= \frac{1}{(1)^2}=1](https://tex.z-dn.net/?f=I%3D%20%5Cfrac%7B1%7D%7Br%5E2%7D%3D%20%5Cfrac%7B1%7D%7B%281%29%5E2%7D%3D1%20%20)
The intensity at r=3 m will be
![I= \frac{1}{r^2}= \frac{1}{(3)^2}= \frac{1}{9}](https://tex.z-dn.net/?f=I%3D%20%5Cfrac%7B1%7D%7Br%5E2%7D%3D%20%5Cfrac%7B1%7D%7B%283%29%5E2%7D%3D%20%5Cfrac%7B1%7D%7B9%7D%20%20%20)
Therefore, the sound intensity has decreased by a factor
![1/9](https://tex.z-dn.net/?f=1%2F9)
.
Answer:
The kinetic energy when the film vault landed is 12744000J.
Explanation:
The kinetic energy is defined as:
(1)
Where m is the mass and v is the velocity.
By means of equation 1, the kinetic energy of the film vault when it landed can be determined
But ![1 J = kg.m^{2}/s^{2}](https://tex.z-dn.net/?f=1%20J%20%3D%20kg.m%5E%7B2%7D%2Fs%5E%7B2%7D)
![k_{e} = 12744000J](https://tex.z-dn.net/?f=k_%7Be%7D%20%3D%2012744000J)
Hence, the kinetic energy when the film vault landed is 12744000J.
The block on the table will move towards the right when the given unbalanced force act on the object. Option C is correct.
<h2>
</h2><h2>
Unbalanced Force:</h2>
When the force acting on the object is not equalized by the opposite force.
<h3>Net force: </h3>
It is defined as the vector sum of all forces acting on the object at an instance.
![F = \vec F_1+\vec F_2+.....](https://tex.z-dn.net/?f=F%20%3D%20%5Cvec%20F_1%2B%5Cvec%20F_2%2B.....)
Where,
- net force
- Force acting on the right = 10 N
- Force acting towards left = -8 N
Put the values in the formula,
![F = 10 +(-8)\\\\F = 2](https://tex.z-dn.net/?f=F%20%3D%2010%20%2B%28-8%29%5C%5C%5C%5CF%20%3D%202)
Since the net force is positive it means the move towards the right.
Therefore, the block on the table will move towards the right when the given unbalanced force act on the object.
Learn more about Unbalanced force:
brainly.com/question/1269006
Answer:
15 m/s
Explanation:
Given data
Initial velocity= 0m/s----------since the cart was at rest
Final velocity = 30m/s
time= 30 seconds
Required
the average speed
We know that the sum of the initial and final velocity is divided by 2 to find the average velocity
average velocity= 0+30/2
average velocity= 30/2
average velocity= 15 m/s
Hence the average velocity is 15 m/s
Generally, the nucleus of an atom has a positive CHARGE because of the protons (not sure what you mean by nature) which helps attract the electrons the nucleus but it stays within it's electron cloud.
It cannot have the same charges as electrons (being negative) as the electrons would be repelled and the atom would lose it's structure.
I hope this answers the question.