Answer:

Explanation:
From the question we are told that
Mass 
Height 
Generally the equation for velocity before impact is is is mathematically given by



Generally the equation for Kinetic Energy is is mathematically given by




The wires is what is needed to put together the whole thing, kinda like glue when you're gluing a piece of paper on it.
Anyways, the battery is the main source and main energy per say.
That energy that comes from the battery, thanks to the wires, it can transfer that said energy to both the switch and light bulb.
And as you flick the switch, it depends of how you put it together, there's two options, turning the light bulb on or turning it off.
Though it doesn't mean that since the light bulb is connected to the battery makes the bulb turn on no matter what since the switch can cancel the main source's energy.
- Ouma :>
I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
67.8 turns needed by the secondary coil to run the bulb.
<u>Explanation</u>:
We know that,



For calculating number of turns

Given that,



We need to find the number of turns in the secondary winding
to run the bulb at 120W 
Firstly find the secondary voltage in the transformer use, 






Now, finding the number of turns in secondary coil. Use, 




The number of turns in the secondary winding are 67.8 turns.