Answer :
Step-by-step explanation:
Hey there!
According to the question;
Mass of an object (m) = 630 kg
Volume of an object (v) = 7m³
We know that;
[tex]density = \frac{mass(kg) \: }{volume( {m}^{3} )} [/tex]
or, density = (630/7) kg/m³
Therefore, density of the substance is 90kg/m².
Hope it helps!