Tin is Sn, atomic number 47 is Silver, Mass of sodium is 22.9 u
1. 
Explanation:
We have:
voltage in the primary coil
voltage in the secondary coil
The efficiency of the transformer is 100%: this means that the power in the primary coil and in the secondary coil are equal

where I1 and I2 are the currents in the two coils. Re-arranging the equation, we find

which means that the current in the secondary coil is 14% of the value of the current in the primary coil.
2. 5.7 V
We can solve the problem by using the transformer equation:

where:
Np = 400 is the number of turns in the primary coil
Ns = 19 is the number of turns in the secondary coil
Vp = 120 V is the voltage in the primary coil
Vs = ? is the voltage in the secondary coil
Re-arranging the formula and substituting the numbers, we find:

Meters ?? or just a variable
0N. The net force acting on this firework is 0.
The key to solve this problem is using the net force formula based on the diagram shown in the image. Fnet = F1 + F2.....Fn.
Based on the free-body diagram, we have:
The force of gases is Fgases = 9,452N
The force of the rocket Frocket = -9452
Then, the net force acting is:
Fnet = Fgases + Frocket
Fnet = 9,452N - 9,452N = 0N
We see black colour in absence of light. Black colour absoorbs all the light, ( just opposite of white) and hence we do not see any colour. Black colour is also related to darkness.