well power is equal to work multiplied by time so .. 900j divided by 15 s will give you 60 Watt as your answer

The fundamental unit among them (not derived) is :
The answer is B. The specific heat means the heat amount the substance needs to absorb when the temperature increases 1℃. The high specific heat means that it needs a huge amount of heat when increase just 1℃. For A, the dissolved salts can help decrease the freezing point.
The answer would be sedimentary rock because sedimentary is made up of small grains and also formed by deposition...