K = C + 273, so 27°C = 27+273 = 300 K
1 dg = 100 mg, so 20 dg = 20×100 = 2,000 mg
        
             
        
        
        
Finding acceleration= final speed-initial speed/time taken (or A=V-U\T)
Finial speed= 27.8s
Initial speed= 0s
Time taken= 5.15 
So..
27.8-0/5.15= 5.40m/s (rounded to two decimal places)
        
             
        
        
        
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 :> 
 
        
             
        
        
        
It's a form of mechanical energy