The frequency will not change
C) above, the Earth's core is about the melting point of iron.
Explanation:
The given data is as follows.
Velocity of bullet,
= 814.8 m/s
Observer distance from marksman, d = 24.7 m
Let us assume that time necessary for report of rifle to reach the observer is t and will be calculated as follows.
t =
(velocity in air = 343 m/s)
= 0.072 sec
Now, before the observer hears the report the distance traveled by the bullet is as follows.

= 
= 58.66
= 59 (approx)
Thus, we can conclude that each bullet will travel a distance of 59 m.
A surface in which is flat or very soft to the touch and reduces splinters or anything sticking out, having an surface which does not have lumps, or indentations.
Answer:
Answered
Explanation:
Part A
According to Faraday's law the induced emf in coil is equal to negative of its rate of change of magnetic flux time the number of turns in the coil.
= 
When an emf generated by a change of magnetic flux, produced current of whose magnetic field opposes the change which produces it.
By the above equation the correct options are 1,2 and 4
Part B
Large signals of frequency of 60Hz are measured by osciloscope.
Hence the correct option is part 1.