Question

Tectonic plates are large segments of the Earth’s crust that move slowly. Suppose that one such plate has an average speed of 4.0 cm/year. (a) What distance does it move in 1 s at this speed? (b) What is its speed in kilometers per million years?

a) 0.0004 m; 4.0 km/Myr
b) 4.0 m; 4000 km/Myr
c) 0.04 m; 40 km/Myr
d) 40 m; 4.0 km/Myr

Answer 1

Tectonic plates can move at different speeds. At a speed of 4.0 cm/year, a plate would move a distance of 0.0004 meters in 1 second. The speed of the plate in kilometers per million years is 4.0 km/Myr.

Step-by-step explanation:

Tectonic plates are large segments of the Earth's crust that move slowly. In 1 second, a plate moving at a speed of 4.0 cm/year would cover a distance of 0.0004 meters (4.0 cm is equal to 0.04 meters).

To find its speed in kilometers per million years, we can convert the average speed to kilometers per year by dividing it by 100,000 (since there are 100,000 centimeters in a kilometer), giving a speed of 0.00004 km/year. Then, to find the speed in kilometers per million years, we multiply the speed by a factor of 1 million. Therefore, the speed of the plate is 4.0 km/Myr (kilometers per million years).