Final answer:
The substance the student found at the beach has a calculated density of 3.7 g/cm³, derived from its mass of 148 g and volume of 40 cm³. To identify the substance, this value would be compared with a density table.
Step-by-step explanation:
To determine what type of substance the student found at the beach, we can calculate the density of the object using the formula for density, D = m/V. Given that the mass (m) of the object is 148 g and the volume (V) is 40 cm³, the density (D) can be calculated as follows:
D = m/V
D = 148 g / 40 cm³
D = 3.7 g/cm³
After calculating the density, we would compare this value to a table of known densities to identify the substance. If the table is not provided, we can infer from common substances that a density of 3.7 g/cm³ could be indicative of a variety of minerals or rocks commonly found at the beach.