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) 1.268×10⁻⁷ cm/sec

b) 40 km/million years.

Explanation:

Speed of tectonic plate = 4.0 cm/year

a) Convert the year to seconds

1 year = 365 days × 24 hours × 60 minutes × 60 seconds

⇒1 year = 31536000 seconds

So,

Distance plate will move in 1 second is 1.268×10⁻⁷ cm/sec

b) Convert cm to km

So, in 1 year it will move 0.00004 km

Hence in 1 million years is will move

0.00004 × 10⁶ = 40 km/million years.

Speed in kilometers per million years is 40 km/million years.