Answer:
Density = 1.67 g/cm³
New Temperature = 10°C ⇔ 283K
Step-by-step explanation:
a. Density of a substance can be described as the mass (in grams) of a substance per litre (in mL or cm³) of liquid displaced.
Hence: Density = mass ÷ volume
Density = 25 ÷ 15
Density = 1.67 g/cm³
b. If the object is cooled to half of its original temperature, the new temperature is assumed to be half of the room temperature
Hence, the substance's new temperature will be = 20÷2
=10°C ⇔ 283K (i.e 10 + 273)