Answer:
(A-) Number of turns in secondary coil will be<u> less than 125.</u>
(B-) EXPLAIN- The voltage is to be lowered.<u> The voltage will be reduced from 120 to 9 volts.</u> As a result, a<u> step down transformer </u>will be used, indicating that the secondary coil's number of turns would be less than 125.
(C-)<u> The number of turns on the secondary coil is 12.5</u>
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Explanation:
- STEP DOWN TRANSFORMER - A step-down transformer transforms high voltage (HV) and low current from the transformer's primary side to low voltage (LV) and high current on the secondary side. A phase down transformer is the opposite of this.
In electrical networks and transmission lines, a step-down transformer can be used in a number of ways.
<u>Step down transformer formula-</u>

We are given with the -
Primary voltage
= 120V
Secondary voltage 
Number of primary turns 
- <u>To calculate the number of turns on the secondary coil -</u>
Since , the transformer ratio is given as -

So, the number of turns on the secondary coil is - 
Putting , the given values -:

= 12.5
<u>Therefore , the number of turns on secondary coil is 12.5 .</u>
Answer:2m
Explanation:
Wavelength=velocity/frequency
Wavelength=4/2=2m
We have that F=ma from the 2nd Newton law where F is the force, m is the mass and a is the acceleration. Suppose we have that F' is the new force and m' is the new mass. Then, we have that a'=F'/m' still, by rearranging Newton's law. We are given that F'=2F and m'=m/2. Hence,

But now, we have from F=ma, that a=F/m and we are given that a=1m/s^2.
We can substitute thus, a'=4a=4*1m/s^2=4m/s^2.
The duck at 12m/s has a greater speed than the heron which travels at 10m/s