Okay while for:
2. D= m/v , so there 2.62g/ml= 50.0g/v, so i mulplity v to both sides so now its V*2.62g/ml= 50.0g, then i divided 2.62g/ml from both sides so that leave the equation as V=50.0g/2.62g/ml. And i got that there is 19.08mls needed.
3. i used the same formula D=M/V, but first i changed L= 10.6mm to 1.06cm, W= 0.15cm, and H=1.248*10^-2 Km to 1248*10^-5cm. Then I mulplity L*W*H=0.0198432cm^3. So, then D= 13.6g/0.0198432cm^3. So the Density=685g/cm^3
1. I just don't understand it.