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 5750 km on a side and 28 km deep and that the rock has an average mass density of 2900 kg/m. The continent is moving at the rate of about 4.2 cm/ year. What is the mass of the continent? (answer in units of kg.)

A) 8.73×10^24 kg
B) 1.26×10^25 kg
C) 2.05×10 ^25 kg
D) 3.58×10^25 kg

Answer 1

The mass of the North American continent is approximately 2.68 x 10^24 kg.

Step-by-step explanation:

To calculate the mass of the North American continent, we can use the formula:

mass = density x volume

Volume = (length)^2 x depth

Converting the units to meters:

length = 5750 km = 5,750,000 m

depth = 28 km = 28,000 m

Plugging the values into the formula:

Volume = (5,750,000 m)^2 x 28,000 m = 9.24125 x 10^20 m^3

mass = 2900 kg/m^3 x 9.24125 x 10^20 m^3 = 2.6786125 x 10^24 kg

Therefore, the mass of the continent is approximately 2.68 x 10^24 kg.