Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and
when moving towards observer
With
of 76 then taking speed in air as 343 m/s we have


Similarly, with
of 65 we have

Now

v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain

The sun is a star (a giant ball of burning gases).
Answer:
B'= 3.333 B
Explanation:
Lets take
Initial area = A
Magnetic field = B
The area after compression
A'=0.3 A
Magnetic field = B'
We know that flux ,Ф
Ф = B A
Given that flux is constant so
B A = B' A'
B A=B' x 0.3 A
B'= 3.333 B
It means that magnetic field will increase.
Answer:
The equation which describes conservation of charge is 
Explanation:
The law of conservation charge states that for an isolated system that sum of initial charges is equal to sum of final charges, that is the total charge is conserved.
let the sum of initial charges = 
let the sum of the final charges = 

Therefore, the equation which describes conservation of charge is 
Well, if i am correct. a substance is:
a particular kind of matter with uniform properties
or...
the real physical matter of which a person or thing consists and which has a tangible, solid presence.
choose which ever you like better:)