Answer:
A hydrometer is an instrument used to determine specific gravity
Power is the rate of doing work.
Its unit is joules/second.
That unit is used so often that a new word was adopted for it.
1 joule/sec = 1 watt
I'll assume you are looking for the mass of the object, since that is the missing piece of the puzzle.
The important equation for heat and energy is
Energy = mass × specific heat × change in temperature
Things we know:
Energy needed is 350 J.
Specific heat = 1.2 J/g°C
Temp. change = (30-20)°
Now we just need to plug those in and rearrange the formula to find the mass!
350 = mass × 1.2 × 10
