College Physics 2.7 – The rate at which the North American and European continents are moving apart


The North American and European continents are moving apart at a rate of about 3 cm/y. At this rate how long will it take them to drift 500 km farther apart than they are at present?


Solution:

We know that the formula for velocity is

\displaystyle \text{velocity}=\frac{\text{displacement}}{\text{time}}

If we rearrange the formula and solve for time, we come up with

\displaystyle \text{time}=\frac{\text{displacement}}{\text{velocity}}

Substituting the given values,

\displaystyle \Delta \text{t}=\frac{500\:\text{km}}{3\:\text{cm/year}}

\displaystyle =\frac{5\times 10^5\text{ m}}{3\:\text{cm/year}}\times \frac{100\:\text{cm}}{1\:\text{m}}

\displaystyle =1.67\times 10^7\text{years}

Therefore, the time it will take is about \displaystyle 1.67\times 10^{7}\ \text{years}.