Chapter U1, Problem 1STP

Interpretation Introduction

Interpretation:

The statement that correctly defines the density of zinc block coated with copper needs to be determined. It is given that the density of zinc is 7.1 g/cm³ and the density of copper is 9.0 g/cm³.

Concept introduction:

Density is a parameter that compare the amount of matter a substance has with respect to its volume.

A substance with more matter in given volume has high density and less matter in the same amount of the volume has low density.

The formula of Density is represented as follows:

$Density=\frac{Mass}{Volume}$

Answer to Problem 1STP

Option: (C) The density of the block is between 7.1g/cm³and 9.0/cm³

Explanation of Solution

Reason for correct option:

If the zinc is coated with the Cu then its density must lie in between these two metals because it does not exceed the density of zinc and copper.

Reasons for incorrect options:

(a) The density of zinc is 7.1 g/cm³ thus, the zinc block coated with copper will have higher density than this.

With the same reason option (b) is also incorrect as the density of block cannot be less than the density of pure zinc.

Now, the density of copper is 9.0 g/cm³ which is coated on the zinc block. Thus, the density of box cannot be exactly same as that of copper.

The density of any substance does not directly change due to addition any substance in it. It depends on the change in volume and mass.

Conclusion

Reasons for incorrect options:

(a) The density of zinc is 7.1 g/cm³ thus, the zinc block coated with copper will have higher density than this.

With the same reason option (b) is also incorrect as the density of block cannot be less than the density of pure zinc.

Now, the density of copper is 9.0 g/cm³ which is coated on the zinc block. Thus, the density of box cannot be exactly same as that of copper.

The density of any substance does not directly change due to addition any substance in it. It depends on the change in volume and mass.