is the intensity of the sound.
Answer: Option B
<u>Explanation:</u>
The range of sound intensity that people can recognize is so large (including 13 magnitude levels). The intensity of the weakest audible noise is called the hearing threshold. (intensity about
). Because it is difficult to imagine numbers in such a large range, it is advisable to use a scale from 0 to 100.
This is the goal of the decibel scale (dB). Because logarithm has the property of recording a large number and returning a small number, the dB scale is based on a logarithmic scale. The scale is defined so that the hearing threshold has intensity level of sound as 0.

Where,
I = Intensity of the sound produced
= Standard Intensity of sound of 60 decibels = 
So for 19 decibels, determine I as follows,



When log goes to other side, express in 10 to the power of that side value,


Answer:
At the lowest point in the oscillation, the momentum is zero.
At the lowest point in the oscillation, 
Explanation:
Since spring block system is performing to and fro motion along straight line
So here we can say at the lowest position of its path the velocity will become zero.
So we can say that momentum of the spring block system is given as


Also we know that after reaching the lowest point the block will again go up towards its mean position
So at the lowest point of the spring block system the block will move upwards again
So this will accelerate upwards hence


Answer: Work can be calculated with the equation: Work = Force × Distance. The SI unit for work is the joule (J), or Newton • meter (N • m). One joule equals the amount of work that is done when 1 N of force moves an object over a distance of 1 m.
Explanation:
Answer: 211.059 m
Explanation:
We have the following data:
The angle at which the ball leaves the bat
The initial velocity of the ball
The acceleration due gravity
We need to find how far (horizontally) the ball travels in the air: 
Firstly we need to know this velocity has two components:
<u>Horizontally:</u>
(1)
(2)
<u>Vertically:</u>
(3)
(4)
On the other hand, when we talk about parabolic movement (as in this situation) the ball reaches its maximum height just in the middle of this parabola, when
and the time
is half the time it takes the complete parabolic path.
So, if we use the following equation, we will find
:
(5)
Isolating
:
(6)
(7)
(8)
Now that we have the time it takes to the ball to travel half of is path, we can find the total time
it takes the complete parabolic path, which is twice
:
(9)
With this result in mind, we can finally calculate how far the ball travels in the air:
(10)
Substituting (2) and (9) in (10):
(11)
Finally: