Question

Tectonic plates are large segments of Earth's crust that move slowly. Suppose one such plate has an average speed of 4.0 cm/yr. (a) What distance does it move in 1.0 s at this speed? (b) What is its speed in kilometers per million years?

Answer 1

(A)
`1.268* 10^(-9)m`

(B)
`40km/million\ year`

Step-by-step explanation:

We have given speed is 4 cm/year

We know that 1 m = 100 cm

And 1 year =
`3.154* 10^7sec`

So speed in
`4cm/year=4* (0.01m)/(3.154* 10^7sec)=1.268* 10^(-9)m/sec`

(A) Time is given t =1 sec

We have to find the distance

Distance is equal to , distance = speed × time =
`=1.268* 10^(-9)* 1=1.268* 10^(-9)m`

(B) Now we have to find the speed in km/million year

As 1 km = 1000 m

And 1 m = 100 cm

So 1 km = 100000 m

`1million\ year=10^6year`

So speed in km/million year will be

`4cm/year=4* (10^(-5)km)/(10^(-6)million\ year)=40km/million\ year`