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 5400 km on a side and 32 km deep and that the rock has an average mass density of 2900 kg/m3 . The continent is moving at the rate of about 4.4 cm/year. What is the mass of the continent? (answer in units of kg)

A) 1.47×10^24 kg
B) 2.64×10^24 kg
C) 3.83×10^24 kg
D) 5.62×10^24 kg

Answer 1

To find the mass of the North American continent, we need to calculate the volume of the slab of rock and then multiply it by the average mass density. The mass of the North American continent is approximately 2.88 x 10^21 kg.

Step-by-step explanation:

To find the mass of the North American continent, we need to calculate the volume of the slab of rock and then multiply it by the average mass density. The volume of the slab can be calculated by multiplying its length, width, and depth.

Volume = 5400 km x 5400 km x 32 km = 993,280,000 km³

Converting km³ to m³, we get:

Volume = 9.9328 x 10^17 m³

Finally, to find the mass, we multiply the volume by the average mass density:

Mass = 9.9328 x 10^17 m³ x 2900 kg/m³ = 2.878272 x 10^21 kg

Therefore, the mass of the North American continent is approximately 2.88 x 10^21 kg.