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

Answer:

1.35×10⁻⁷ m

37.278 mi/My

Explanation:

Speed of the tectonic plate= 6 cm/yr

Converting to seconds

$6=\frac{6}{365.25\times 24\times 60\times 60}$

So in one second it will move

$\frac{6}{365.25\times 24\times 60\times 60}$

In 71 seconds

$71\times \frac{6}{365.25\times 24\times 60\times 60}=1.35\times 10^{-5}\ cm$

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

$6\times 6.213\times 10^{-6}\times 10^6=37.278\ mi/My$

Speed of the tectonic plate is 37.278 mi/My