Question

Tectonic plates are large segments of the earth's crust that move slowly. Suppose one such plate has an average speed of 6.0 cm per year. (a) What distance does it move in 71 seconds at this speed?

m
(b) What is its speed in miles per million years?
mi/My

Answer 1

1.35×10⁻⁷ m

37.278 mi/My

Step-by-step explanation:

Speed of the tectonic plate= 6 cm/yr

Converting to seconds

`6=(6)/(365.25* 24* 60* 60)`

So in one second it will move

`(6)/(365.25* 24* 60* 60)`

In 71 seconds

`71* (6)/(365.25* 24* 60* 60)=1.35* 10^(-5)\ cm`

The tectonic plate will move 1.35×10⁻⁵ cm or 1.35×10⁻⁷ m

Convert to mi/My

1 cm = 6.213×10⁻⁶ mi

1 M = 10⁶ years

`6* 6.213* 10^(-6)* 10^6=37.278\ mi/My`

Speed of the tectonic plate is 37.278 mi/My