The Gravitationa potential energy of the mass (PEG) is given by:

where
m is the mass
g is the gravitational acceleration
h is the heigth of the mass above the reference level (the ground)
In this problem,

and

, therefore the gravitational potential energy of the mass is:
Answer:
The beat frequency is 0.0019 MHz.
Explanation:
Given that,
Velocity = 0.32 m/s
Frequency = 4.40 MHz
Speed of wave = 1540 m/s
We need to calculate the frequency
Case (I),
Observer is moving away from the source
Using Doppler's effect

Where, v' = speed of observer
Put the value into the formula


Case (II),
Cell is as the source of sound of frequency f' and it moving away from the observer.
Using formula of frequency



We need to calculate the beat frequency


Hence, The beat frequency is 0.0019 MHz.
Answer:
The magnitude of electron acceleration is

Explanation:
Given:
Distance from the wire to the field point
m
Speed of electron 
Current
A
For finding the acceleration,
First find the magnetic field due to wire,

Where 

T
The magnetic force exerted on the electron passing through straight wire,

N
From the newton's second law

Where
mass of electron
kg
So acceleration is given by,



Therefore, the magnitude of electron acceleration is

Hello.
The answer is:
It creates a spark.
Then thespark can sometimes start a fire or other serious problems.
Have a nice day