Question

The current theory of the structure of the earth, called plate tectonics, tells us that the continents are in constant motion. Assume that the North American continent can be represented by a slab of rock 4350 km on a side and 38 km deep and that the rock has an average mass density of 2700 kg/m³. The continent is moving at the rate of about 1.4 cm/year. What is the mass of the continent? Answer in units of kg.

Answer 1

The mass of the North American continent, represented as a slab of rock 4350 km on a side and 38 km deep, with a density of 2700 kg/m³, can be calculated by multiplying the volume of the rock by its density.

Step-by-step explanation:

The student's question pertains to calculating the mass of the North American continent based on its dimensions and average mass density, considering the theory of plate tectonics.

To calculate the mass of the continent, we use the formula:

Mass = Density × Volume

First, we need to find the volume of the North American slab of rock. Since the dimensions given are in kilometers and the density is in kg/m³, we need to convert the dimensions to meters:

4350 km = 4,350,000 m (since 1 km = 1000 m)
38 km = 38,000 m

Volume = Length × Width × Height = 4,350,000 m × 4,350,000 m × 38,000 m.

Now, multiply the volume by the density (2700 kg/m³) to find the mass:

Mass = 2700 kg/m³ × Volume

Without performing the actual multiplication, we know that the mass will be a very large number presented in kilograms (kg).