Answer:
We know that loudness is directly proportional to amplitude and SI unit of amplitude is Decibel So unit of loudness is decibel
Given:
m = 0.14 kg
v = 18 m/s
To find:
Kinetic energy= ?
Explanation:
Kinetic energy of the object is possessed when the object is in motion. It is define as the work done required to accelerate a body from rest to motion. Unit of energy is Joule and it is same as unit of work done. Energy is nothing but the capacity to do work.
Solution:
Kinetic energy of the ball is given by,
Kinetic energy = 
m = 0.14 kg
v = 18 m/s
Kinetic energy = 
Kinetic energy = 226.8 Joule
Answer:
From the formular of magnetic force:

• F » magnetic force, B » magnetic flux density, I » current, l » length [ assume l = 1 m ]
