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 4600 km on a side and 25 km deep and that the rock has an average mass density of 2720 kg/m³. The continent is moving at the rate of about 1.8 cm/year. What is the mass of the continent? Answer in units of kg.

Answer 1

To calculate the mass of the North American continent represented as a slab of rock, multiply its volume by its density, yielding approximately 1.44 × 10^21 kg.

Step-by-step explanation:

The question asks for the mass of the North American continent assuming it can be represented by a slab of rock with given dimensions and mass density. To find the mass, we use the formula for the volume of a cube (length × width × height) and then multiply by the density to find the mass.

First, convert the given side length from kilometers to meters:
4600 km = 4,600,000 meters. Then, calculate the volume:
Volume = 4,600,000 m × 4,600,000 m × 25,000 m = 5.29 × 1017 m3. Next, calculate the mass:
Mass = Volume × Density = 5.29 × 1017 m3 × 2720 kg/m3 = 1.44 × 1021 kg.

Therefore, the mass of the North American continent would be approximately 1.44 × 1021 kg.