Question

4 form a hypothesis: how do you think cutting up a material will affect its density?

Explanation:

Density is defined as mass per unit volume ($
ho = \frac{m}{V}$). When a material is cut, its total mass and total volume both decrease proportionally (assuming no material is lost). Since density depends on the ratio of mass to volume, and both change by the same factor (e.g., cutting a piece into half: mass becomes $\frac{m}{2}$, volume becomes $\frac{V}{2}$, so $
ho = \frac{\frac{m}{2}}{\frac{V}{2}}=\frac{m}{V}$), the density remains unchanged. So the hypothesis is that cutting up a material will not affect its density.

Answer:

Cutting up a material will not affect its density because density is a ratio of mass to volume, and both mass and volume of the material (or its pieces) change proportionally when cut, keeping the density constant.