Question

Tectonic plates are large segments of the Earth's crust that move slowly. Suppose one such plate has an average speed of 4.8 cm per year. (a) What distance does it move in 55 seconds at this speed? m (b) What is its speed in miles per million years? mi/million yr

Answer 1

(a) Average speed of tectonic plates, v = 4.8 cm / year

= (4.8 x 10^-2) m / year

= (4.8 x 10^-2) / (365 x 24 x 60 x 60) m/sec

So, distance moved by the tectonic plates in 55 seconds, d = v*t

= [(4.8 x 10^-2) / (365 x 24 x 60 x 60)] * 55 m

= 8.37 x 10^-8 m

(b) Speed of the plate in mi/million yr, v = (4.8 x 10^-2) m / year

= (4.8 x 10^-2 x 0.0006214) / 10^-6 mi/million yr

= 29.827 mi/million yr