<span>If there isn't any force then the normal contact force will be
N=m*g=7.5*9.81=73.58N
which is 73.58-23=50.58N less
so, there the person must pull at 23 degree upward
break down the tension in two components, vertical and horizontal.
vertical tension= 50.58=T*sin23
T=50.58/sin23=129.45N</span>
Explanation:
Given that,
Distance 1, r = 100 m
Intensity, 
If distance 2, r' = 25 m
We need to find the intensity and the intensity level at 25 meters. Intensity and a distance r is given by :
.........(1)
Let I' is the intensity at r'. So,
............(2)
From equation (1) and (2) :



Intensity level is given by :
, 

dB = 32.96 dB
Hence, this is the required solution.
Mechanical
waves are oscillation of matter, they are important because they all
transfer energy from one place to another. There are 2 types of
mechanical waves. A transverse wave where the particles vibrate
perpendicular to the direction of energy travel and a longitudinal
wave where particle vibrations are parallel to the direction of the
energy transfer.
I
hope it helps, Regards.
<h2>Hello!</h2>
The answer is: B. Kinetic energy
<h2>
Why?</h2>
Since the ball is falling, speed increases because the gravity acceleration is acting. When speed increases, the kinetic energy increases too, so the ball is gaining kinetic energy.
The gravity acceleration is equal to
, it means that when falling, the ball will increase it's speed 9.81m every second.
We can calculate the kinetic energy by using the following formula:

Where:

Have a nice day!
<h2 />
Because way back, when there were some kinds of plants that made
their own food, and other kinds of plants that depended on dinosaurs or
people to bring them food, guess which ones starved and became extinct,
and which ones lived and are still among us today.